Reformat all files with isort and black

docs/_ext/djangodummy/settings.py

@@ -5,11 +5,9 @@
 # so the docs root won't be detected by find_packages()
 
 # Display sane URLs in the docs:
-STATIC_URL = '/static/'
+STATIC_URL = "/static/"
 
 # Avoid error for missing the secret key
-SECRET_KEY = 'docs'
+SECRET_KEY = "docs"
 
-INSTALLED_APPS = [
-    'django.contrib.contenttypes',
-]
+INSTALLED_APPS = ["django.contrib.contenttypes"]

docs/conf.py

@@ -11,17 +11,18 @@
 # All configuration values have a default; values that are commented out
 # serve to show the default.
 
-import sys
 import os
+import sys
+
 import django
 import sphinx_rtd_theme
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
-sys.path.insert(0, os.path.abspath('_ext'))
-sys.path.insert(0, os.path.abspath('..'))
-os.environ['DJANGO_SETTINGS_MODULE'] = 'djangodummy.settings'
+sys.path.insert(0, os.path.abspath("_ext"))
+sys.path.insert(0, os.path.abspath(".."))
+os.environ["DJANGO_SETTINGS_MODULE"] = "djangodummy.settings"
 
 django.setup()
 
@@ -33,36 +34,36 @@ django.setup()
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
 extensions = [
-    'sphinx.ext.autodoc',
-    'sphinx.ext.graphviz',
-    'sphinx.ext.intersphinx',
-    'sphinxcontrib_django',
+    "sphinx.ext.autodoc",
+    "sphinx.ext.graphviz",
+    "sphinx.ext.intersphinx",
+    "sphinxcontrib_django",
 ]
 
 # Add any paths that contain templates here, relative to this directory.
-templates_path = ['_templates']
+templates_path = ["_templates"]
 
 # The suffix of source filenames.
-source_suffix = '.rst'
+source_suffix = ".rst"
 
 # The encoding of source files.
 # source_encoding = 'utf-8-sig'
 
 # The master toctree document.
-master_doc = 'index'
+master_doc = "index"
 
 # General information about the project.
-project = u'django-polymorphic'
-copyright = u'2013, Bert Constantin, Chris Glass, Diederik van der Boor'
+project = u"django-polymorphic"
+copyright = u"2013, Bert Constantin, Chris Glass, Diederik van der Boor"
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
 # built documents.
 #
 # The short X.Y version.
-version = '2.0.3'
+version = "2.0.3"
 # The full version, including alpha/beta/rc tags.
-release = '2.0.3'
+release = "2.0.3"
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
@@ -76,7 +77,7 @@ release = '2.0.3'
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
-exclude_patterns = ['_build']
+exclude_patterns = ["_build"]
 
 # The reST default role (used for this markup: `text`) to use for all documents.
 # default_role = None
@@ -93,7 +94,7 @@ exclude_patterns = ['_build']
 # show_authors = False
 
 # The name of the Pygments (syntax highlighting) style to use.
-pygments_style = 'sphinx'
+pygments_style = "sphinx"
 
 # A list of ignored prefixes for module index sorting.
 # modindex_common_prefix = []
@@ -103,7 +104,7 @@ pygments_style = 'sphinx'
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
-html_theme = 'sphinx_rtd_theme'
+html_theme = "sphinx_rtd_theme"
 html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
 
 # Theme options are theme-specific and customize the look and feel of a theme
@@ -133,7 +134,7 @@ html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = ['_static']
+html_static_path = ["_static"]
 
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.
@@ -177,7 +178,7 @@ html_static_path = ['_static']
 # html_file_suffix = None
 
 # Output file base name for HTML help builder.
-htmlhelp_basename = 'django-polymorphicdoc'
+htmlhelp_basename = "django-polymorphicdoc"
 
 
 # -- Options for LaTeX output --------------------------------------------------
@@ -185,10 +186,8 @@ htmlhelp_basename = 'django-polymorphicdoc'
 latex_elements = {
     # The paper size ('letterpaper' or 'a4paper').
     #'papersize': 'letterpaper',
-
     # The font size ('10pt', '11pt' or '12pt').
     #'pointsize': '10pt',
-
     # Additional stuff for the LaTeX preamble.
     #'preamble': '',
 }
@@ -196,8 +195,13 @@ latex_elements = {
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, documentclass [howto/manual]).
 latex_documents = [
-    ('index', 'django-polymorphic.tex', u'django-polymorphic Documentation',
-     u'Bert Constantin, Chris Glass, Diederik van der Boor', 'manual'),
+    (
+        "index",
+        "django-polymorphic.tex",
+        u"django-polymorphic Documentation",
+        u"Bert Constantin, Chris Glass, Diederik van der Boor",
+        "manual",
+    )
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
@@ -226,8 +230,13 @@ latex_documents = [
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
 man_pages = [
-    ('index', 'django-polymorphic', u'django-polymorphic Documentation',
-     [u'Bert Constantin, Chris Glass, Diederik van der Boor'], 1)
+    (
+        "index",
+        "django-polymorphic",
+        u"django-polymorphic Documentation",
+        [u"Bert Constantin, Chris Glass, Diederik van der Boor"],
+        1,
+    )
 ]
 
 # If true, show URL addresses after external links.
@@ -240,9 +249,15 @@ man_pages = [
 # (source start file, target name, title, author,
 #  dir menu entry, description, category)
 texinfo_documents = [
-    ('index', 'django-polymorphic', u'django-polymorphic Documentation',
-     u'Bert Constantin, Chris Glass, Diederik van der Boor', 'django-polymorphic', 'One line description of project.',
-     'Miscellaneous'),
+    (
+        "index",
+        "django-polymorphic",
+        u"django-polymorphic Documentation",
+        u"Bert Constantin, Chris Glass, Diederik van der Boor",
+        "django-polymorphic",
+        "One line description of project.",
+        "Miscellaneous",
+    )
 ]
 
 # Documents to append as an appendix to all manuals.
@@ -258,8 +273,8 @@ texinfo_documents = [
 # Example configuration for intersphinx: refer to the Python standard library.
 intersphinx_mapping = {
     #'http://docs.python.org/': None,
-    'https://docs.djangoproject.com/en/stable': 'https://docs.djangoproject.com/en/stable/_objects',
+    "https://docs.djangoproject.com/en/stable": "https://docs.djangoproject.com/en/stable/_objects"
 }
 
 # autodoc settings
-autodoc_member_order = 'groupwise'
+autodoc_member_order = "groupwise"

example/example/settings.py

@@ -10,46 +10,47 @@ MANAGERS = ADMINS
 PROJECT_ROOT = os.path.dirname(os.path.dirname(__file__))
 
 DATABASES = {
-    'default': {
-        'ENGINE': 'django.db.backends.sqlite3',
-        'NAME': os.path.join(PROJECT_ROOT, 'example.db'),
+    "default": {
+        "ENGINE": "django.db.backends.sqlite3",
+        "NAME": os.path.join(PROJECT_ROOT, "example.db"),
     }
 }
 
 SITE_ID = 1
 
 # Make this unique, and don't share it with anybody.
-SECRET_KEY = '5$f%)&a4tc*bg(79+ku!7o$kri-duw99@hq_)va^_kaw9*l)!7'
+SECRET_KEY = "5$f%)&a4tc*bg(79+ku!7o$kri-duw99@hq_)va^_kaw9*l)!7"
 
 
 # Language
 # TIME_ZONE = 'America/Chicago'
-LANGUAGE_CODE = 'en-us'
+LANGUAGE_CODE = "en-us"
 USE_I18N = True
 USE_L10N = True
 USE_TZ = True
 
 # Paths
-MEDIA_ROOT = ''
-MEDIA_URL = '/media/'
-STATIC_ROOT = ''
-STATIC_URL = '/static/'
+MEDIA_ROOT = ""
+MEDIA_URL = "/media/"
+STATIC_ROOT = ""
+STATIC_URL = "/static/"
 
 # Apps
 STATICFILES_FINDERS = (
-    'django.contrib.staticfiles.finders.FileSystemFinder',
-    'django.contrib.staticfiles.finders.AppDirectoriesFinder',
+    "django.contrib.staticfiles.finders.FileSystemFinder",
+    "django.contrib.staticfiles.finders.AppDirectoriesFinder",
 )
 
 MIDDLEWARE = (
-    'django.middleware.common.CommonMiddleware',
-    'django.contrib.sessions.middleware.SessionMiddleware',
-    'django.middleware.csrf.CsrfViewMiddleware',
-    'django.contrib.auth.middleware.AuthenticationMiddleware',
-    'django.contrib.messages.middleware.MessageMiddleware',
+    "django.middleware.common.CommonMiddleware",
+    "django.contrib.sessions.middleware.SessionMiddleware",
+    "django.middleware.csrf.CsrfViewMiddleware",
+    "django.contrib.auth.middleware.AuthenticationMiddleware",
+    "django.contrib.messages.middleware.MessageMiddleware",
 )
 
-TEMPLATES=[{
+TEMPLATES = [
+    {
         "BACKEND": "django.template.backends.django.DjangoTemplates",
         "DIRS": (),
         "OPTIONS": {
@@ -67,48 +68,44 @@ TEMPLATES=[{
                 "django.contrib.auth.context_processors.auth",
             ),
         },
-}]
+    }
+]
 
-ROOT_URLCONF = 'example.urls'
+ROOT_URLCONF = "example.urls"
 
-WSGI_APPLICATION = 'example.wsgi.application'
+WSGI_APPLICATION = "example.wsgi.application"
 
 INSTALLED_APPS = (
-    'django.contrib.auth',
-    'django.contrib.admin',
-    'django.contrib.contenttypes',
-    'django.contrib.sessions',
-    'django.contrib.messages',
-    'django.contrib.staticfiles',
-
-    'polymorphic',      # needed if you want to use the polymorphic admin
-    'pexp',             # this Django app is for testing and experimentation; not needed otherwise
-    'orders',
+    "django.contrib.auth",
+    "django.contrib.admin",
+    "django.contrib.contenttypes",
+    "django.contrib.sessions",
+    "django.contrib.messages",
+    "django.contrib.staticfiles",
+    "polymorphic",  # needed if you want to use the polymorphic admin
+    "pexp",  # this Django app is for testing and experimentation; not needed otherwise
+    "orders",
 )
 
-TEST_RUNNER = 'django.test.runner.DiscoverRunner'  # silence system checks
+TEST_RUNNER = "django.test.runner.DiscoverRunner"  # silence system checks
 
 # Logging configuration
 LOGGING = {
-    'version': 1,
-    'disable_existing_loggers': False,
-    'filters': {
-        'require_debug_false': {
-            '()': 'django.utils.log.RequireDebugFalse'
+    "version": 1,
+    "disable_existing_loggers": False,
+    "filters": {"require_debug_false": {"()": "django.utils.log.RequireDebugFalse"}},
+    "handlers": {
+        "mail_admins": {
+            "level": "ERROR",
+            "filters": ["require_debug_false"],
+            "class": "django.utils.log.AdminEmailHandler",
         }
     },
-    'handlers': {
-        'mail_admins': {
-            'level': 'ERROR',
-            'filters': ['require_debug_false'],
-            'class': 'django.utils.log.AdminEmailHandler'
+    "loggers": {
+        "django.request": {
+            "handlers": ["mail_admins"],
+            "level": "ERROR",
+            "propagate": True,
         }
     },
-    'loggers': {
-        'django.request': {
-            'handlers': ['mail_admins'],
-            'level': 'ERROR',
-            'propagate': True,
-        },
-    }
 }

example/example/urls.py

@@ -6,6 +6,6 @@ from django.views.generic import RedirectView
 admin.autodiscover()
 
 urlpatterns = [
-    url(r'^admin/', admin.site.urls),
-    url(r'^$', RedirectView.as_view(url=reverse_lazy('admin:index'), permanent=False)),
+    url(r"^admin/", admin.site.urls),
+    url(r"^$", RedirectView.as_view(url=reverse_lazy("admin:index"), permanent=False)),
 ]

example/example/wsgi.py

@@ -15,12 +15,14 @@ framework.
 """
 import os
 
-os.environ.setdefault("DJANGO_SETTINGS_MODULE", "example.settings")
-
 # This application object is used by any WSGI server configured to use this
 # file. This includes Django's development server, if the WSGI_APPLICATION
 # setting points here.
 from django.core.wsgi import get_wsgi_application
+
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "example.settings")
+
+
 application = get_wsgi_application()
 
 # Apply WSGI middleware here.

example/orders/admin.py

@@ -1,7 +1,8 @@
 from django.contrib import admin
 
 from polymorphic.admin import PolymorphicInlineSupportMixin, StackedPolymorphicInline
-from .models import Order, Payment, CreditCardPayment, BankPayment, SepaPayment
+
+from .models import BankPayment, CreditCardPayment, Order, Payment, SepaPayment
 
 
 class CreditCardPaymentInline(StackedPolymorphicInline.Child):
@@ -24,11 +25,7 @@ class PaymentInline(StackedPolymorphicInline):
     """
 
     model = Payment
-    child_inlines = (
-        CreditCardPaymentInline,
-        BankPaymentInline,
-        SepaPaymentInline,
-    )
+    child_inlines = (CreditCardPaymentInline, BankPaymentInline, SepaPaymentInline)
 
 
 @admin.register(Order)
@@ -39,5 +36,5 @@ class OrderAdmin(PolymorphicInlineSupportMixin, admin.ModelAdmin):
     To make sure the inlines are properly handled,
     the ``PolymorphicInlineSupportMixin`` is needed to
     """
-    inlines = (PaymentInline,)
 
+    inlines = (PaymentInline,)

example/orders/migrations/0001_initial.py

@@ -6,83 +6,148 @@ from django.db import migrations, models
 
 class Migration(migrations.Migration):
 
-    dependencies = [
-        ('contenttypes', '0002_remove_content_type_name'),
-    ]
+    dependencies = [("contenttypes", "0002_remove_content_type_name")]
 
     operations = [
         migrations.CreateModel(
-            name='Order',
+            name="Order",
             fields=[
-                ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
-                ('title', models.CharField(max_length=200, verbose_name='Title')),
+                (
+                    "id",
+                    models.AutoField(
+                        verbose_name="ID",
+                        serialize=False,
+                        auto_created=True,
+                        primary_key=True,
+                    ),
+                ),
+                ("title", models.CharField(max_length=200, verbose_name="Title")),
             ],
             options={
-                'ordering': ('title',),
-                'verbose_name': 'Organisation',
-                'verbose_name_plural': 'Organisations',
+                "ordering": ("title",),
+                "verbose_name": "Organisation",
+                "verbose_name_plural": "Organisations",
             },
         ),
         migrations.CreateModel(
-            name='Payment',
+            name="Payment",
             fields=[
-                ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
-                ('currency', models.CharField(default=b'USD', max_length=3)),
-                ('amount', models.DecimalField(max_digits=10, decimal_places=2)),
+                (
+                    "id",
+                    models.AutoField(
+                        verbose_name="ID",
+                        serialize=False,
+                        auto_created=True,
+                        primary_key=True,
+                    ),
+                ),
+                ("currency", models.CharField(default=b"USD", max_length=3)),
+                ("amount", models.DecimalField(max_digits=10, decimal_places=2)),
             ],
-            options={
-                'verbose_name': 'Payment',
-                'verbose_name_plural': 'Payments',
-            },
+            options={"verbose_name": "Payment", "verbose_name_plural": "Payments"},
         ),
         migrations.CreateModel(
-            name='BankPayment',
+            name="BankPayment",
             fields=[
-                ('payment_ptr', models.OneToOneField(parent_link=True, auto_created=True, primary_key=True, serialize=False, on_delete=models.CASCADE, to='orders.Payment')),
-                ('bank_name', models.CharField(max_length=100)),
-                ('swift', models.CharField(max_length=20)),
+                (
+                    "payment_ptr",
+                    models.OneToOneField(
+                        parent_link=True,
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        on_delete=models.CASCADE,
+                        to="orders.Payment",
+                    ),
+                ),
+                ("bank_name", models.CharField(max_length=100)),
+                ("swift", models.CharField(max_length=20)),
             ],
             options={
-                'verbose_name': 'Bank Payment',
-                'verbose_name_plural': 'Bank Payments',
+                "verbose_name": "Bank Payment",
+                "verbose_name_plural": "Bank Payments",
             },
-            bases=('orders.payment',),
+            bases=("orders.payment",),
         ),
         migrations.CreateModel(
-            name='CreditCardPayment',
+            name="CreditCardPayment",
             fields=[
-                ('payment_ptr', models.OneToOneField(parent_link=True, auto_created=True, primary_key=True, serialize=False, on_delete=models.CASCADE, to='orders.Payment')),
-                ('card_type', models.CharField(max_length=10)),
-                ('expiry_month', models.PositiveSmallIntegerField(choices=[(1, 'jan'), (2, 'feb'), (3, 'mar'), (4, 'apr'), (5, 'may'), (6, 'jun'), (7, 'jul'), (8, 'aug'), (9, 'sep'), (10, 'oct'), (11, 'nov'), (12, 'dec')])),
-                ('expiry_year', models.PositiveIntegerField()),
+                (
+                    "payment_ptr",
+                    models.OneToOneField(
+                        parent_link=True,
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        on_delete=models.CASCADE,
+                        to="orders.Payment",
+                    ),
+                ),
+                ("card_type", models.CharField(max_length=10)),
+                (
+                    "expiry_month",
+                    models.PositiveSmallIntegerField(
+                        choices=[
+                            (1, "jan"),
+                            (2, "feb"),
+                            (3, "mar"),
+                            (4, "apr"),
+                            (5, "may"),
+                            (6, "jun"),
+                            (7, "jul"),
+                            (8, "aug"),
+                            (9, "sep"),
+                            (10, "oct"),
+                            (11, "nov"),
+                            (12, "dec"),
+                        ]
+                    ),
+                ),
+                ("expiry_year", models.PositiveIntegerField()),
             ],
             options={
-                'verbose_name': 'Credit Card Payment',
-                'verbose_name_plural': 'Credit Card Payments',
+                "verbose_name": "Credit Card Payment",
+                "verbose_name_plural": "Credit Card Payments",
             },
-            bases=('orders.payment',),
+            bases=("orders.payment",),
         ),
         migrations.CreateModel(
-            name='SepaPayment',
+            name="SepaPayment",
             fields=[
-                ('payment_ptr', models.OneToOneField(parent_link=True, auto_created=True, primary_key=True, serialize=False, on_delete=models.CASCADE, to='orders.Payment')),
-                ('iban', models.CharField(max_length=34)),
-                ('bic', models.CharField(max_length=11)),
+                (
+                    "payment_ptr",
+                    models.OneToOneField(
+                        parent_link=True,
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        on_delete=models.CASCADE,
+                        to="orders.Payment",
+                    ),
+                ),
+                ("iban", models.CharField(max_length=34)),
+                ("bic", models.CharField(max_length=11)),
             ],
             options={
-                'verbose_name': 'Bank Payment',
-                'verbose_name_plural': 'Bank Payments',
+                "verbose_name": "Bank Payment",
+                "verbose_name_plural": "Bank Payments",
             },
-            bases=('orders.payment',),
+            bases=("orders.payment",),
         ),
         migrations.AddField(
-            model_name='payment',
-            name='order',
-            field=models.ForeignKey(to='orders.Order', on_delete=models.CASCADE),
+            model_name="payment",
+            name="order",
+            field=models.ForeignKey(to="orders.Order", on_delete=models.CASCADE),
         ),
         migrations.AddField(
-            model_name='payment',
-            name='polymorphic_ctype',
-            field=models.ForeignKey(related_name='polymorphic_orders.payment_set+', editable=False, on_delete=models.CASCADE, to='contenttypes.ContentType', null=True),
+            model_name="payment",
+            name="polymorphic_ctype",
+            field=models.ForeignKey(
+                related_name="polymorphic_orders.payment_set+",
+                editable=False,
+                on_delete=models.CASCADE,
+                to="contenttypes.ContentType",
+                null=True,
+            ),
         ),
     ]

example/orders/models.py

@@ -11,12 +11,13 @@ class Order(models.Model):
     """
     An example order that has polymorphic relations
     """
+
     title = models.CharField(_("Title"), max_length=200)
 
     class Meta:
         verbose_name = _("Organisation")
         verbose_name_plural = _("Organisations")
-        ordering = ('title',)
+        ordering = ("title",)
 
     def __str__(self):
         return self.title
@@ -27,8 +28,9 @@ class Payment(PolymorphicModel):
     """
     A generic payment model.
     """
+
     order = models.ForeignKey(Order, on_delete=models.CASCADE)
-    currency = models.CharField(default='USD', max_length=3)
+    currency = models.CharField(default="USD", max_length=3)
     amount = models.DecimalField(max_digits=10, decimal_places=2)
 
     class Meta:
@@ -43,6 +45,7 @@ class CreditCardPayment(Payment):
     """
     Credit card
     """
+
     MONTH_CHOICES = [(i, n) for i, n in sorted(MONTHS_3.items())]
 
     card_type = models.CharField(max_length=10)
@@ -58,6 +61,7 @@ class BankPayment(Payment):
     """
     Payment by bank
     """
+
     bank_name = models.CharField(max_length=100)
     swift = models.CharField(max_length=20)
 
@@ -70,6 +74,7 @@ class SepaPayment(Payment):
     """
     Payment by SEPA (EU)
     """
+
     iban = models.CharField(max_length=34)
     bic = models.CharField(max_length=11)
 

example/pexp/admin.py

@@ -1,6 +1,11 @@
 from django.contrib import admin
-from polymorphic.admin import PolymorphicParentModelAdmin, PolymorphicChildModelAdmin, PolymorphicChildModelFilter
+
 from pexp.models import *
+from polymorphic.admin import (
+    PolymorphicChildModelAdmin,
+    PolymorphicChildModelFilter,
+    PolymorphicParentModelAdmin,
+)
 
 
 class ProjectAdmin(PolymorphicParentModelAdmin):
@@ -14,11 +19,7 @@ class ProjectChildAdmin(PolymorphicChildModelAdmin):
 
     # On purpose, only have the shared fields here.
     # The fields of the derived model should still be displayed.
-    base_fieldsets = (
-        ("Base fields", {
-            'fields': ('topic',)
-        }),
-    )
+    base_fieldsets = (("Base fields", {"fields": ("topic",)}),)
 
 
 admin.site.register(Project, ProjectAdmin)

example/pexp/management/commands/p2cmd.py

@@ -7,12 +7,12 @@ import sys
 import time
 from pprint import pprint
 from random import Random
+
 from django.core.management import BaseCommand
 from django.db import connection
 
 from pexp.models import *
 
-
 rnd = Random()
 
 
@@ -24,7 +24,7 @@ def show_queries():
     connection.queries = []
 
 
-def print_timing(func, message='', iterations=1):
+def print_timing(func, message="", iterations=1):
     def wrapper(*arg):
         results = []
         connection.queries_log.clear()
@@ -36,13 +36,12 @@ def print_timing(func, message='', iterations=1):
         res_sum = 0
         for r in results:
             res_sum += r
-        print("%s%-19s: %.4f ms, %i queries (%i times)" % (
-            message, func.func_name,
-            res_sum,
-            len(connection.queries),
-            iterations
-        ))
+        print(
+            "%s%-19s: %.4f ms, %i queries (%i times)"
+            % (message, func.func_name, res_sum, len(connection.queries), iterations)
+        )
         sys.stdout.flush()
+
     return wrapper
 
 
@@ -52,9 +51,9 @@ class Command(BaseCommand):
     def handle_noargs(self, **options):
         if False:
             TestModelA.objects.all().delete()
-            a = TestModelA.objects.create(field1='A1')
-            b = TestModelB.objects.create(field1='B1', field2='B2')
-            c = TestModelC.objects.create(field1='C1', field2='C2', field3='C3')
+            a = TestModelA.objects.create(field1="A1")
+            b = TestModelB.objects.create(field1="B1", field2="B2")
+            c = TestModelC.objects.create(field1="C1", field2="C2", field3="C3")
             connection.queries_log.clear()
             print(TestModelC.base_objects.all())
             show_queries()
@@ -64,7 +63,9 @@ class Command(BaseCommand):
             for i in range(1000):
                 a = TestModelA.objects.create(field1=str(i % 100))
                 b = TestModelB.objects.create(field1=str(i % 100), field2=str(i % 200))
-                c = TestModelC.objects.create(field1=str(i % 100), field2=str(i % 200), field3=str(i % 300))
+                c = TestModelC.objects.create(
+                    field1=str(i % 100), field2=str(i % 200), field3=str(i % 300)
+                )
                 if i % 100 == 0:
                     print(i)
 
@@ -77,9 +78,9 @@ class Command(BaseCommand):
         return
 
         NormalModelA.objects.all().delete()
-        a = NormalModelA.objects.create(field1='A1')
-        b = NormalModelB.objects.create(field1='B1', field2='B2')
-        c = NormalModelC.objects.create(field1='C1', field2='C2', field3='C3')
+        a = NormalModelA.objects.create(field1="A1")
+        b = NormalModelB.objects.create(field1="B1", field2="B2")
+        c = NormalModelC.objects.create(field1="C1", field2="C2", field3="C3")
         qs = TestModelA.objects.raw("SELECT * from pexp_testmodela")
         for o in list(qs):
             print(o)
@@ -87,7 +88,8 @@ class Command(BaseCommand):
 
 def poly_sql_query():
     cursor = connection.cursor()
-    cursor.execute("""
+    cursor.execute(
+        """
         SELECT id, pexp_testmodela.field1, pexp_testmodelb.field2, pexp_testmodelc.field3
         FROM pexp_testmodela
         LEFT OUTER JOIN pexp_testmodelb
@@ -96,18 +98,23 @@ def poly_sql_query():
         ON pexp_testmodelb.testmodela_ptr_id = pexp_testmodelc.testmodelb_ptr_id
         WHERE pexp_testmodela.field1=%i
         ORDER BY pexp_testmodela.id
-        """ % rnd.randint(0, 100))
+        """
+        % rnd.randint(0, 100)
+    )
     # row=cursor.fetchone()
     return
 
 
 def poly_sql_query2():
     cursor = connection.cursor()
-    cursor.execute("""
+    cursor.execute(
+        """
         SELECT id, pexp_testmodela.field1
         FROM pexp_testmodela
         WHERE pexp_testmodela.field1=%i
         ORDER BY pexp_testmodela.id
-        """ % rnd.randint(0, 100))
+        """
+        % rnd.randint(0, 100)
+    )
     # row=cursor.fetchone()
     return

example/pexp/management/commands/pcmd.py

@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """
 This module is a scratchpad for general development, testing & debugging.
 """
@@ -20,13 +19,15 @@ class Command(NoArgsCommand):
         Project.objects.all().delete()
         a = Project.objects.create(topic="John's gathering")
         b = ArtProject.objects.create(topic="Sculpting with Tim", artist="T. Turner")
-        c = ResearchProject.objects.create(topic="Swallow Aerodynamics", supervisor="Dr. Winter")
-        print Project.objects.all()
-        print
+        c = ResearchProject.objects.create(
+            topic="Swallow Aerodynamics", supervisor="Dr. Winter"
+        )
+        print(Project.objects.all())
+        print("")
 
         TestModelA.objects.all().delete()
-        a = TestModelA.objects.create(field1='A1')
-        b = TestModelB.objects.create(field1='B1', field2='B2')
-        c = TestModelC.objects.create(field1='C1', field2='C2', field3='C3')
-        print TestModelA.objects.all()
-        print
+        a = TestModelA.objects.create(field1="A1")
+        b = TestModelB.objects.create(field1="B1", field2="B2")
+        c = TestModelC.objects.create(field1="C1", field2="C2", field3="C3")
+        print(TestModelA.objects.all())
+        print("")

example/pexp/management/commands/polybench.py

@@ -3,14 +3,14 @@
 This module is a scratchpad for general development, testing & debugging
 """
 
-import time
 import sys
+import time
+from pprint import pprint
 
 from django.core.management import BaseCommand
 from django.db import connection
-from pprint import pprint
-from pexp.models import *
 
+from pexp.models import *
 
 num_objects = 1000
 
@@ -27,7 +27,7 @@ def show_queries():
 # benchmark wrappers
 
 
-def print_timing(func, message='', iterations=1):
+def print_timing(func, message="", iterations=1):
     def wrapper(*arg):
         results = []
         connection.queries_log.clear()
@@ -40,28 +40,31 @@ def print_timing(func, message='', iterations=1):
         for r in results:
             res_sum += r
         median = res_sum / len(results)
-        print("%s%-19s: %.0f ms, %i queries" % (
-            message, func.func_name,
-            median,
-            len(connection.queries) / len(results)
-        ))
+        print(
+            "%s%-19s: %.0f ms, %i queries"
+            % (message, func.func_name, median, len(connection.queries) / len(results))
+        )
         sys.stdout.flush()
+
     return wrapper
 
 
 def run_vanilla_any_poly(func, iterations=1):
-    f = print_timing(func, '     ', iterations)
+    f = print_timing(func, "     ", iterations)
     f(NormalModelC)
-    f = print_timing(func, 'poly ', iterations)
+    f = print_timing(func, "poly ", iterations)
     f(TestModelC)
 
 
 ###################################################################################
 # benchmarks
 
+
 def bench_create(model):
     for i in range(num_objects):
-        model.objects.create(field1='abc' + str(i), field2='abcd' + str(i), field3='abcde' + str(i))
+        model.objects.create(
+            field1="abc" + str(i), field2="abcd" + str(i), field3="abcde" + str(i)
+        )
     # print 'count:',model.objects.count()
 
 
@@ -94,6 +97,7 @@ def bench_load2_short(model):
 def bench_delete(model):
     model.objects.all().delete()
 
+
 ###################################################################################
 # Command
 
@@ -108,7 +112,7 @@ class Command(BaseCommand):
             (bench_load1, 5),
             (bench_load1_short, 5),
             (bench_load2, 5),
-            (bench_load2_short, 5)
+            (bench_load2_short, 5),
         ]
         for f, iterations in func_list:
             run_vanilla_any_poly(f, iterations=iterations)

example/pexp/management/commands/polymorphic_create_test_data.py

@@ -15,5 +15,7 @@ class Command(BaseCommand):
         Project.objects.all().delete()
         o = Project.objects.create(topic="John's gathering")
         o = ArtProject.objects.create(topic="Sculpting with Tim", artist="T. Turner")
-        o = ResearchProject.objects.create(topic="Swallow Aerodynamics", supervisor="Dr. Winter")
+        o = ResearchProject.objects.create(
+            topic="Swallow Aerodynamics", supervisor="Dr. Winter"
+        )
         print(Project.objects.all())

example/pexp/migrations/0001_initial.py

@@ -2,181 +2,295 @@
 from __future__ import unicode_literals
 
 from django.db import migrations, models
+
 import polymorphic.showfields
 
 
 class Migration(migrations.Migration):
 
-    dependencies = [
-        ('contenttypes', '0002_remove_content_type_name'),
-    ]
+    dependencies = [("contenttypes", "0002_remove_content_type_name")]
 
     operations = [
         migrations.CreateModel(
-            name='NormalModelA',
+            name="NormalModelA",
             fields=[
-                ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
-                ('field1', models.CharField(max_length=10)),
+                (
+                    "id",
+                    models.AutoField(
+                        verbose_name="ID",
+                        serialize=False,
+                        auto_created=True,
+                        primary_key=True,
+                    ),
+                ),
+                ("field1", models.CharField(max_length=10)),
             ],
         ),
         migrations.CreateModel(
-            name='Project',
+            name="Project",
             fields=[
-                ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
-                ('topic', models.CharField(max_length=30)),
+                (
+                    "id",
+                    models.AutoField(
+                        verbose_name="ID",
+                        serialize=False,
+                        auto_created=True,
+                        primary_key=True,
+                    ),
+                ),
+                ("topic", models.CharField(max_length=30)),
             ],
-            options={
-                'abstract': False,
-            },
+            options={"abstract": False},
             bases=(polymorphic.showfields.ShowFieldContent, models.Model),
         ),
         migrations.CreateModel(
-            name='ProxyBase',
+            name="ProxyBase",
             fields=[
-                ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
-                ('title', models.CharField(max_length=200)),
-                ('polymorphic_ctype', models.ForeignKey(related_name='polymorphic_pexp.proxybase_set+', editable=False, on_delete=models.CASCADE, to='contenttypes.ContentType', null=True)),
+                (
+                    "id",
+                    models.AutoField(
+                        verbose_name="ID",
+                        serialize=False,
+                        auto_created=True,
+                        primary_key=True,
+                    ),
+                ),
+                ("title", models.CharField(max_length=200)),
+                (
+                    "polymorphic_ctype",
+                    models.ForeignKey(
+                        related_name="polymorphic_pexp.proxybase_set+",
+                        editable=False,
+                        on_delete=models.CASCADE,
+                        to="contenttypes.ContentType",
+                        null=True,
+                    ),
+                ),
             ],
-            options={
-                'ordering': ('title',),
-            },
+            options={"ordering": ("title",)},
         ),
         migrations.CreateModel(
-            name='TestModelA',
+            name="TestModelA",
             fields=[
-                ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
-                ('field1', models.CharField(max_length=10)),
+                (
+                    "id",
+                    models.AutoField(
+                        verbose_name="ID",
+                        serialize=False,
+                        auto_created=True,
+                        primary_key=True,
+                    ),
+                ),
+                ("field1", models.CharField(max_length=10)),
             ],
-            options={
-                'abstract': False,
-            },
+            options={"abstract": False},
             bases=(polymorphic.showfields.ShowFieldTypeAndContent, models.Model),
         ),
         migrations.CreateModel(
-            name='UUIDModelA',
+            name="UUIDModelA",
             fields=[
-                ('uuid_primary_key', models.UUIDField(serialize=False, primary_key=True)),
-                ('field1', models.CharField(max_length=10)),
+                (
+                    "uuid_primary_key",
+                    models.UUIDField(serialize=False, primary_key=True),
+                ),
+                ("field1", models.CharField(max_length=10)),
             ],
-            options={
-                'abstract': False,
-            },
+            options={"abstract": False},
             bases=(polymorphic.showfields.ShowFieldTypeAndContent, models.Model),
         ),
         migrations.CreateModel(
-            name='ArtProject',
+            name="ArtProject",
             fields=[
-                ('project_ptr', models.OneToOneField(parent_link=True, auto_created=True, primary_key=True, serialize=False, on_delete=models.CASCADE, to='pexp.Project')),
-                ('artist', models.CharField(max_length=30)),
+                (
+                    "project_ptr",
+                    models.OneToOneField(
+                        parent_link=True,
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        on_delete=models.CASCADE,
+                        to="pexp.Project",
+                    ),
+                ),
+                ("artist", models.CharField(max_length=30)),
             ],
-            options={
-                'abstract': False,
-            },
-            bases=('pexp.project',),
+            options={"abstract": False},
+            bases=("pexp.project",),
         ),
         migrations.CreateModel(
-            name='NormalModelB',
+            name="NormalModelB",
             fields=[
-                ('normalmodela_ptr', models.OneToOneField(parent_link=True, auto_created=True, primary_key=True, serialize=False, on_delete=models.CASCADE, to='pexp.NormalModelA')),
-                ('field2', models.CharField(max_length=10)),
+                (
+                    "normalmodela_ptr",
+                    models.OneToOneField(
+                        parent_link=True,
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        on_delete=models.CASCADE,
+                        to="pexp.NormalModelA",
+                    ),
+                ),
+                ("field2", models.CharField(max_length=10)),
             ],
-            bases=('pexp.normalmodela',),
+            bases=("pexp.normalmodela",),
         ),
         migrations.CreateModel(
-            name='ResearchProject',
+            name="ResearchProject",
             fields=[
-                ('project_ptr', models.OneToOneField(parent_link=True, auto_created=True, primary_key=True, serialize=False, on_delete=models.CASCADE, to='pexp.Project')),
-                ('supervisor', models.CharField(max_length=30)),
+                (
+                    "project_ptr",
+                    models.OneToOneField(
+                        parent_link=True,
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        on_delete=models.CASCADE,
+                        to="pexp.Project",
+                    ),
+                ),
+                ("supervisor", models.CharField(max_length=30)),
             ],
-            options={
-                'abstract': False,
-            },
-            bases=('pexp.project',),
+            options={"abstract": False},
+            bases=("pexp.project",),
         ),
         migrations.CreateModel(
-            name='TestModelB',
+            name="TestModelB",
             fields=[
-                ('testmodela_ptr', models.OneToOneField(parent_link=True, auto_created=True, primary_key=True, serialize=False, on_delete=models.CASCADE, to='pexp.TestModelA')),
-                ('field2', models.CharField(max_length=10)),
+                (
+                    "testmodela_ptr",
+                    models.OneToOneField(
+                        parent_link=True,
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        on_delete=models.CASCADE,
+                        to="pexp.TestModelA",
+                    ),
+                ),
+                ("field2", models.CharField(max_length=10)),
             ],
-            options={
-                'abstract': False,
-            },
-            bases=('pexp.testmodela',),
+            options={"abstract": False},
+            bases=("pexp.testmodela",),
         ),
         migrations.CreateModel(
-            name='UUIDModelB',
+            name="UUIDModelB",
             fields=[
-                ('uuidmodela_ptr', models.OneToOneField(parent_link=True, auto_created=True, primary_key=True, serialize=False, on_delete=models.CASCADE, to='pexp.UUIDModelA')),
-                ('field2', models.CharField(max_length=10)),
+                (
+                    "uuidmodela_ptr",
+                    models.OneToOneField(
+                        parent_link=True,
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        on_delete=models.CASCADE,
+                        to="pexp.UUIDModelA",
+                    ),
+                ),
+                ("field2", models.CharField(max_length=10)),
             ],
-            options={
-                'abstract': False,
-            },
-            bases=('pexp.uuidmodela',),
+            options={"abstract": False},
+            bases=("pexp.uuidmodela",),
         ),
         migrations.AddField(
-            model_name='uuidmodela',
-            name='polymorphic_ctype',
-            field=models.ForeignKey(related_name='polymorphic_pexp.uuidmodela_set+', editable=False, on_delete=models.CASCADE, to='contenttypes.ContentType', null=True),
+            model_name="uuidmodela",
+            name="polymorphic_ctype",
+            field=models.ForeignKey(
+                related_name="polymorphic_pexp.uuidmodela_set+",
+                editable=False,
+                on_delete=models.CASCADE,
+                to="contenttypes.ContentType",
+                null=True,
+            ),
         ),
         migrations.AddField(
-            model_name='testmodela',
-            name='polymorphic_ctype',
-            field=models.ForeignKey(related_name='polymorphic_pexp.testmodela_set+', editable=False, on_delete=models.CASCADE, to='contenttypes.ContentType', null=True),
+            model_name="testmodela",
+            name="polymorphic_ctype",
+            field=models.ForeignKey(
+                related_name="polymorphic_pexp.testmodela_set+",
+                editable=False,
+                on_delete=models.CASCADE,
+                to="contenttypes.ContentType",
+                null=True,
+            ),
         ),
         migrations.AddField(
-            model_name='project',
-            name='polymorphic_ctype',
-            field=models.ForeignKey(related_name='polymorphic_pexp.project_set+', editable=False, on_delete=models.CASCADE, to='contenttypes.ContentType', null=True),
+            model_name="project",
+            name="polymorphic_ctype",
+            field=models.ForeignKey(
+                related_name="polymorphic_pexp.project_set+",
+                editable=False,
+                on_delete=models.CASCADE,
+                to="contenttypes.ContentType",
+                null=True,
+            ),
         ),
         migrations.CreateModel(
-            name='ProxyA',
-            fields=[
-            ],
-            options={
-                'proxy': True,
-            },
-            bases=('pexp.proxybase',),
+            name="ProxyA", fields=[], options={"proxy": True}, bases=("pexp.proxybase",)
         ),
         migrations.CreateModel(
-            name='ProxyB',
-            fields=[
-            ],
-            options={
-                'proxy': True,
-            },
-            bases=('pexp.proxybase',),
+            name="ProxyB", fields=[], options={"proxy": True}, bases=("pexp.proxybase",)
         ),
         migrations.CreateModel(
-            name='NormalModelC',
+            name="NormalModelC",
             fields=[
-                ('normalmodelb_ptr', models.OneToOneField(parent_link=True, auto_created=True, primary_key=True, serialize=False, on_delete=models.CASCADE, to='pexp.NormalModelB')),
-                ('field3', models.CharField(max_length=10)),
+                (
+                    "normalmodelb_ptr",
+                    models.OneToOneField(
+                        parent_link=True,
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        on_delete=models.CASCADE,
+                        to="pexp.NormalModelB",
+                    ),
+                ),
+                ("field3", models.CharField(max_length=10)),
             ],
-            bases=('pexp.normalmodelb',),
+            bases=("pexp.normalmodelb",),
         ),
         migrations.CreateModel(
-            name='TestModelC',
+            name="TestModelC",
             fields=[
-                ('testmodelb_ptr', models.OneToOneField(parent_link=True, auto_created=True, primary_key=True, serialize=False, on_delete=models.CASCADE, to='pexp.TestModelB')),
-                ('field3', models.CharField(max_length=10)),
-                ('field4', models.ManyToManyField(related_name='related_c', to='pexp.TestModelB')),
+                (
+                    "testmodelb_ptr",
+                    models.OneToOneField(
+                        parent_link=True,
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        on_delete=models.CASCADE,
+                        to="pexp.TestModelB",
+                    ),
+                ),
+                ("field3", models.CharField(max_length=10)),
+                (
+                    "field4",
+                    models.ManyToManyField(
+                        related_name="related_c", to="pexp.TestModelB"
+                    ),
+                ),
             ],
-            options={
-                'abstract': False,
-            },
-            bases=('pexp.testmodelb',),
+            options={"abstract": False},
+            bases=("pexp.testmodelb",),
         ),
         migrations.CreateModel(
-            name='UUIDModelC',
+            name="UUIDModelC",
             fields=[
-                ('uuidmodelb_ptr', models.OneToOneField(parent_link=True, auto_created=True, primary_key=True, serialize=False, on_delete=models.CASCADE, to='pexp.UUIDModelB')),
-                ('field3', models.CharField(max_length=10)),
+                (
+                    "uuidmodelb_ptr",
+                    models.OneToOneField(
+                        parent_link=True,
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        on_delete=models.CASCADE,
+                        to="pexp.UUIDModelB",
+                    ),
+                ),
+                ("field3", models.CharField(max_length=10)),
             ],
-            options={
-                'abstract': False,
-            },
-            bases=('pexp.uuidmodelb',),
+            options={"abstract": False},
+            bases=("pexp.uuidmodelb",),
         ),
     ]

example/pexp/models.py

@@ -8,6 +8,7 @@ from polymorphic.showfields import ShowFieldContent, ShowFieldTypeAndContent
 
 class Project(ShowFieldContent, PolymorphicModel):
     """Polymorphic model"""
+
     topic = models.CharField(max_length=30)
 
 
@@ -21,6 +22,7 @@ class ResearchProject(Project):
 
 class UUIDModelA(ShowFieldTypeAndContent, PolymorphicModel):
     """UUID as primary key example"""
+
     uuid_primary_key = models.UUIDField(primary_key=True)
     field1 = models.CharField(max_length=10)
 
@@ -35,17 +37,17 @@ class UUIDModelC(UUIDModelB):
 
 class ProxyBase(PolymorphicModel):
     """Proxy model example - a single table with multiple types."""
+
     title = models.CharField(max_length=200)
 
     def __unicode__(self):
         return u"<ProxyBase[type={0}]: {1}>".format(self.polymorphic_ctype, self.title)
 
     class Meta:
-        ordering = ('title',)
+        ordering = ("title",)
 
 
 class ProxyA(ProxyBase):
-
     class Meta:
         proxy = True
 
@@ -54,7 +56,6 @@ class ProxyA(ProxyBase):
 
 
 class ProxyB(ProxyBase):
-
     class Meta:
         proxy = True
 
@@ -64,6 +65,7 @@ class ProxyB(ProxyBase):
 
 # Internals for management command tests
 
+
 class TestModelA(ShowFieldTypeAndContent, PolymorphicModel):
     field1 = models.CharField(max_length=10)
 
@@ -74,11 +76,12 @@ class TestModelB(TestModelA):
 
 class TestModelC(TestModelB):
     field3 = models.CharField(max_length=10)
-    field4 = models.ManyToManyField(TestModelB, related_name='related_c')
+    field4 = models.ManyToManyField(TestModelB, related_name="related_c")
 
 
 class NormalModelA(models.Model):
     """Normal Django inheritance, no polymorphic behavior"""
+
     field1 = models.CharField(max_length=10)
 
 

polymorphic/__init__.py

@@ -13,4 +13,3 @@ try:
     __version__ = pkg_resources.require("django-polymorphic")[0].version
 except pkg_resources.DistributionNotFound:
     __version__ = None  # for RTD among others
-

polymorphic/admin/__init__.py

@@ -4,44 +4,38 @@ ModelAdmin code to display polymorphic models.
 The admin consists of a parent admin (which shows in the admin with a list),
 and a child admin (which is used internally to show the edit/delete dialog).
 """
-# Admins for the regular models
-from .parentadmin import PolymorphicParentModelAdmin
 from .childadmin import PolymorphicChildModelAdmin
+from .filters import PolymorphicChildModelFilter
 
 # Utils
 from .forms import PolymorphicModelChoiceForm
-from .filters import PolymorphicChildModelFilter
-
-# Inlines
-from .inlines import (
-    PolymorphicInlineModelAdmin,  # base class
-    StackedPolymorphicInline,  # stacked inline
-)
-
-# Helpers for the inlines
-from .helpers import (
-    PolymorphicInlineAdminForm,
-    PolymorphicInlineAdminFormSet,
-    PolymorphicInlineSupportMixin,  # mixin for the regular model admin!
-)
 
 # Expose generic admin features too. There is no need to split those
 # as the admin already relies on contenttypes.
-from .generic import (
-    GenericPolymorphicInlineModelAdmin,  # base class
-    GenericStackedPolymorphicInline,  # stacked inline
-)
+from .generic import GenericPolymorphicInlineModelAdmin  # base class
+from .generic import GenericStackedPolymorphicInline  # stacked inline
+
+# Helpers for the inlines
+from .helpers import PolymorphicInlineSupportMixin  # mixin for the regular model admin!
+from .helpers import PolymorphicInlineAdminForm, PolymorphicInlineAdminFormSet
+
+# Inlines
+from .inlines import PolymorphicInlineModelAdmin  # base class
+from .inlines import StackedPolymorphicInline  # stacked inline
+
+# Admins for the regular models
+from .parentadmin import PolymorphicParentModelAdmin
 
 __all__ = (
-    'PolymorphicParentModelAdmin',
-    'PolymorphicChildModelAdmin',
-    'PolymorphicModelChoiceForm',
-    'PolymorphicChildModelFilter',
-    'PolymorphicInlineAdminForm',
-    'PolymorphicInlineAdminFormSet',
-    'PolymorphicInlineSupportMixin',
-    'PolymorphicInlineModelAdmin',
-    'StackedPolymorphicInline',
-    'GenericPolymorphicInlineModelAdmin',
-    'GenericStackedPolymorphicInline',
+    "PolymorphicParentModelAdmin",
+    "PolymorphicChildModelAdmin",
+    "PolymorphicModelChoiceForm",
+    "PolymorphicChildModelFilter",
+    "PolymorphicInlineAdminForm",
+    "PolymorphicInlineAdminFormSet",
+    "PolymorphicInlineSupportMixin",
+    "PolymorphicInlineModelAdmin",
+    "StackedPolymorphicInline",
+    "GenericPolymorphicInlineModelAdmin",
+    "GenericStackedPolymorphicInline",
 )

polymorphic/admin/childadmin.py

@@ -8,6 +8,7 @@ from django.urls import resolve
 from django.utils.translation import ugettext_lazy as _
 
 from polymorphic.utils import get_base_polymorphic_model
+
 from ..admin import PolymorphicParentModelAdmin
 
 
@@ -46,7 +47,9 @@ class PolymorphicChildModelAdmin(admin.ModelAdmin):
     show_in_index = False
 
     def __init__(self, model, admin_site, *args, **kwargs):
-        super(PolymorphicChildModelAdmin, self).__init__(model, admin_site, *args, **kwargs)
+        super(PolymorphicChildModelAdmin, self).__init__(
+            model, admin_site, *args, **kwargs
+        )
 
         if self.base_model is None:
             self.base_model = get_base_polymorphic_model(model)
@@ -59,19 +62,23 @@ class PolymorphicChildModelAdmin(admin.ModelAdmin):
         #
         # Instead, pass the form unchecked here, because the standard ModelForm will just work.
         # If the derived class sets the model explicitly, respect that setting.
-        kwargs.setdefault('form', self.base_form or self.form)
+        kwargs.setdefault("form", self.base_form or self.form)
 
         # prevent infinite recursion when this is called from get_subclass_fields
         if not self.fieldsets and not self.fields:
-            kwargs.setdefault('fields', '__all__')
+            kwargs.setdefault("fields", "__all__")
 
         return super(PolymorphicChildModelAdmin, self).get_form(request, obj, **kwargs)
 
     def get_model_perms(self, request):
         match = resolve(request.path)
 
-        if not self.show_in_index and match.app_name == 'admin' and match.url_name in ('index', 'app_list'):
-            return {'add': False, 'change': False, 'delete': False}
+        if (
+            not self.show_in_index
+            and match.app_name == "admin"
+            and match.url_name in ("index", "app_list")
+        ):
+            return {"add": False, "change": False, "delete": False}
         return super(PolymorphicChildModelAdmin, self).get_model_perms(request)
 
     @property
@@ -87,10 +94,11 @@ class PolymorphicChildModelAdmin(admin.ModelAdmin):
             "admin/%s/%s/change_form.html" % (app_label, opts.object_name.lower()),
             "admin/%s/change_form.html" % app_label,
             # Added:
-            "admin/%s/%s/change_form.html" % (base_app_label, base_opts.object_name.lower()),
+            "admin/%s/%s/change_form.html"
+            % (base_app_label, base_opts.object_name.lower()),
             "admin/%s/change_form.html" % base_app_label,
             "admin/polymorphic/change_form.html",
-            "admin/change_form.html"
+            "admin/change_form.html",
         ]
 
     @property
@@ -103,13 +111,15 @@ class PolymorphicChildModelAdmin(admin.ModelAdmin):
         base_app_label = base_opts.app_label
 
         return [
-            "admin/%s/%s/delete_confirmation.html" % (app_label, opts.object_name.lower()),
+            "admin/%s/%s/delete_confirmation.html"
+            % (app_label, opts.object_name.lower()),
             "admin/%s/delete_confirmation.html" % app_label,
             # Added:
-            "admin/%s/%s/delete_confirmation.html" % (base_app_label, base_opts.object_name.lower()),
+            "admin/%s/%s/delete_confirmation.html"
+            % (base_app_label, base_opts.object_name.lower()),
             "admin/%s/delete_confirmation.html" % base_app_label,
             "admin/polymorphic/delete_confirmation.html",
-            "admin/delete_confirmation.html"
+            "admin/delete_confirmation.html",
         ]
 
     @property
@@ -125,15 +135,16 @@ class PolymorphicChildModelAdmin(admin.ModelAdmin):
             "admin/%s/%s/object_history.html" % (app_label, opts.object_name.lower()),
             "admin/%s/object_history.html" % app_label,
             # Added:
-            "admin/%s/%s/object_history.html" % (base_app_label, base_opts.object_name.lower()),
+            "admin/%s/%s/object_history.html"
+            % (base_app_label, base_opts.object_name.lower()),
             "admin/%s/object_history.html" % base_app_label,
             "admin/polymorphic/object_history.html",
-            "admin/object_history.html"
+            "admin/object_history.html",
         ]
 
     def _get_parent_admin(self):
         # this returns parent admin instance on which to call response_post_save methods
-        parent_model = self.model._meta.get_field('polymorphic_ctype').model
+        parent_model = self.model._meta.get_field("polymorphic_ctype").model
         if parent_model == self.model:
             # when parent_model is in among child_models, just return super instance
             return super(PolymorphicChildModelAdmin, self)
@@ -149,11 +160,15 @@ class PolymorphicChildModelAdmin(admin.ModelAdmin):
 
                 # Fetch admin instance for model class, see if it's a possible candidate.
                 model_admin = self.admin_site._registry.get(klass)
-                if model_admin is not None and isinstance(model_admin, PolymorphicParentModelAdmin):
+                if model_admin is not None and isinstance(
+                    model_admin, PolymorphicParentModelAdmin
+                ):
                     return model_admin  # Success!
 
             # If we get this far without returning there is no admin available
-            raise ParentAdminNotRegistered("No parent admin was registered for a '{0}' model.".format(parent_model))
+            raise ParentAdminNotRegistered(
+                "No parent admin was registered for a '{0}' model.".format(parent_model)
+            )
 
     def response_post_save_add(self, request, obj):
         return self._get_parent_admin().response_post_save_add(request, obj)
@@ -161,26 +176,28 @@ class PolymorphicChildModelAdmin(admin.ModelAdmin):
     def response_post_save_change(self, request, obj):
         return self._get_parent_admin().response_post_save_change(request, obj)
 
-    def render_change_form(self, request, context, add=False, change=False, form_url='', obj=None):
-        context.update({
-            'base_opts': self.base_model._meta,
-        })
-        return super(PolymorphicChildModelAdmin, self).render_change_form(request, context, add=add, change=change, form_url=form_url, obj=obj)
+    def render_change_form(
+        self, request, context, add=False, change=False, form_url="", obj=None
+    ):
+        context.update({"base_opts": self.base_model._meta})
+        return super(PolymorphicChildModelAdmin, self).render_change_form(
+            request, context, add=add, change=change, form_url=form_url, obj=obj
+        )
 
     def delete_view(self, request, object_id, context=None):
-        extra_context = {
-            'base_opts': self.base_model._meta,
-        }
-        return super(PolymorphicChildModelAdmin, self).delete_view(request, object_id, extra_context)
+        extra_context = {"base_opts": self.base_model._meta}
+        return super(PolymorphicChildModelAdmin, self).delete_view(
+            request, object_id, extra_context
+        )
 
     def history_view(self, request, object_id, extra_context=None):
         # Make sure the history view can also display polymorphic breadcrumbs
-        context = {
-            'base_opts': self.base_model._meta,
-        }
+        context = {"base_opts": self.base_model._meta}
         if extra_context:
             context.update(extra_context)
-        return super(PolymorphicChildModelAdmin, self).history_view(request, object_id, extra_context=context)
+        return super(PolymorphicChildModelAdmin, self).history_view(
+            request, object_id, extra_context=context
+        )
 
     # ---- Extra: improving the form/fieldset default display ----
 
@@ -201,7 +218,7 @@ class PolymorphicChildModelAdmin(admin.ModelAdmin):
         if other_fields:
             return (
                 base_fieldsets[0],
-                (self.extra_fieldset_title, {'fields': other_fields}),
+                (self.extra_fieldset_title, {"fields": other_fields}),
             ) + base_fieldsets[1:]
         else:
             return base_fieldsets
@@ -215,11 +232,13 @@ class PolymorphicChildModelAdmin(admin.ModelAdmin):
         # By not declaring the fields/form in the base class,
         # get_form() will populate the form with all available fields.
         form = self.get_form(request, obj, exclude=exclude)
-        subclass_fields = list(form.base_fields.keys()) + list(self.get_readonly_fields(request, obj))
+        subclass_fields = list(form.base_fields.keys()) + list(
+            self.get_readonly_fields(request, obj)
+        )
 
         # Find which fields are not part of the common fields.
         for fieldset in self.get_base_fieldsets(request, obj):
-            for field in fieldset[1]['fields']:
+            for field in fieldset[1]["fields"]:
                 try:
                     subclass_fields.remove(field)
                 except ValueError:

polymorphic/admin/filters.py

@@ -14,11 +14,12 @@ class PolymorphicChildModelFilter(admin.SimpleListFilter):
 
         list_filter = (PolymorphicChildModelFilter,)
     """
-    title = _('Type')
-    parameter_name = 'polymorphic_ctype'
+
+    title = _("Type")
+    parameter_name = "polymorphic_ctype"
 
     def lookups(self, request, model_admin):
-        return model_admin.get_child_type_choices(request, 'change')
+        return model_admin.get_child_type_choices(request, "change")
 
     def queryset(self, request, queryset):
         try:
@@ -31,5 +32,8 @@ class PolymorphicChildModelFilter(admin.SimpleListFilter):
                 if choice_value == value:
                     return queryset.filter(polymorphic_ctype_id=choice_value)
             raise PermissionDenied(
-                'Invalid ContentType "{0}". It must be registered as child model.'.format(value))
+                'Invalid ContentType "{0}". It must be registered as child model.'.format(
+                    value
+                )
+            )
         return queryset

polymorphic/admin/forms.py

@@ -7,12 +7,15 @@ class PolymorphicModelChoiceForm(forms.Form):
     """
     The default form for the ``add_type_form``. Can be overwritten and replaced.
     """
-    #: Define the label for the radiofield
-    type_label = _('Type')
 
-    ct_id = forms.ChoiceField(label=type_label, widget=AdminRadioSelect(attrs={'class': 'radiolist'}))
+    #: Define the label for the radiofield
+    type_label = _("Type")
+
+    ct_id = forms.ChoiceField(
+        label=type_label, widget=AdminRadioSelect(attrs={"class": "radiolist"})
+    )
 
     def __init__(self, *args, **kwargs):
         # Allow to easily redefine the label (a commonly expected usecase)
         super(PolymorphicModelChoiceForm, self).__init__(*args, **kwargs)
-        self.fields['ct_id'].label = self.type_label
+        self.fields["ct_id"].label = self.type_label

polymorphic/admin/generic.py

@@ -2,14 +2,22 @@ from django.contrib.contenttypes.admin import GenericInlineModelAdmin
 from django.contrib.contenttypes.models import ContentType
 from django.utils.functional import cached_property
 
-from polymorphic.formsets import polymorphic_child_forms_factory, BaseGenericPolymorphicInlineFormSet, GenericPolymorphicFormSetChild
+from polymorphic.formsets import (
+    BaseGenericPolymorphicInlineFormSet,
+    GenericPolymorphicFormSetChild,
+    polymorphic_child_forms_factory,
+)
+
 from .inlines import PolymorphicInlineModelAdmin
 
 
-class GenericPolymorphicInlineModelAdmin(PolymorphicInlineModelAdmin, GenericInlineModelAdmin):
+class GenericPolymorphicInlineModelAdmin(
+    PolymorphicInlineModelAdmin, GenericInlineModelAdmin
+):
     """
     Base class for variation of inlines based on generic foreign keys.
     """
+
     #: The formset class
     formset = BaseGenericPolymorphicInlineFormSet
 
@@ -31,6 +39,7 @@ class GenericPolymorphicInlineModelAdmin(PolymorphicInlineModelAdmin, GenericInl
         """
         Variation for generic inlines.
         """
+
         # Make sure that the GFK fields are excluded from the child forms
         formset_child = GenericPolymorphicFormSetChild
         ct_field = "content_type"
@@ -42,22 +51,24 @@ class GenericPolymorphicInlineModelAdmin(PolymorphicInlineModelAdmin, GenericInl
             Expose the ContentType that the child relates to.
             This can be used for the ``polymorphic_ctype`` field.
             """
-            return ContentType.objects.get_for_model(self.model, for_concrete_model=False)
+            return ContentType.objects.get_for_model(
+                self.model, for_concrete_model=False
+            )
 
         def get_formset_child(self, request, obj=None, **kwargs):
             # Similar to GenericInlineModelAdmin.get_formset(),
             # make sure the GFK is automatically excluded from the form
-            defaults = {
-                "ct_field": self.ct_field,
-                "fk_field": self.ct_fk_field,
-            }
+            defaults = {"ct_field": self.ct_field, "fk_field": self.ct_fk_field}
             defaults.update(kwargs)
-            return super(GenericPolymorphicInlineModelAdmin.Child, self).get_formset_child(request, obj=obj, **defaults)
+            return super(
+                GenericPolymorphicInlineModelAdmin.Child, self
+            ).get_formset_child(request, obj=obj, **defaults)
 
 
 class GenericStackedPolymorphicInline(GenericPolymorphicInlineModelAdmin):
     """
     The stacked layout for generic inlines.
     """
+
     #: The default template to use.
-    template = 'admin/polymorphic/edit_inline/stacked.html'
+    template = "admin/polymorphic/edit_inline/stacked.html"

polymorphic/admin/helpers.py

@@ -5,7 +5,7 @@ This makes sure that admin fieldsets/layout settings are exported to the templat
 """
 import json
 
-from django.contrib.admin.helpers import InlineAdminFormSet, InlineAdminForm, AdminField
+from django.contrib.admin.helpers import AdminField, InlineAdminForm, InlineAdminFormSet
 from django.utils.encoding import force_text
 from django.utils.text import capfirst
 from django.utils.translation import ugettext
@@ -19,11 +19,11 @@ class PolymorphicInlineAdminForm(InlineAdminForm):
     """
 
     def polymorphic_ctype_field(self):
-        return AdminField(self.form, 'polymorphic_ctype', False)
+        return AdminField(self.form, "polymorphic_ctype", False)
 
     @property
     def is_empty(self):
-        return '__prefix__' in self.form.prefix
+        return "__prefix__" in self.form.prefix
 
 
 class PolymorphicInlineAdminFormSet(InlineAdminFormSet):
@@ -32,15 +32,19 @@ class PolymorphicInlineAdminFormSet(InlineAdminFormSet):
     """
 
     def __init__(self, *args, **kwargs):
-        self.request = kwargs.pop('request', None)  # Assigned later via PolymorphicInlineSupportMixin later.
-        self.obj = kwargs.pop('obj', None)
+        self.request = kwargs.pop(
+            "request", None
+        )  # Assigned later via PolymorphicInlineSupportMixin later.
+        self.obj = kwargs.pop("obj", None)
         super(PolymorphicInlineAdminFormSet, self).__init__(*args, **kwargs)
 
     def __iter__(self):
         """
         Output all forms using the proper subtype settings.
         """
-        for form, original in zip(self.formset.initial_forms, self.formset.get_queryset()):
+        for form, original in zip(
+            self.formset.initial_forms, self.formset.get_queryset()
+        ):
             # Output the form
             model = original.get_real_instance_class()
             child_inline = self.opts.get_child_inline_instance(model)
@@ -54,7 +58,7 @@ class PolymorphicInlineAdminFormSet(InlineAdminFormSet):
                 original=original,
                 readonly_fields=self.get_child_readonly_fields(child_inline),
                 model_admin=child_inline,
-                view_on_site_url=view_on_site_url
+                view_on_site_url=view_on_site_url,
             )
 
         # Extra rows, and empty prefixed forms.
@@ -88,22 +92,24 @@ class PolymorphicInlineAdminFormSet(InlineAdminFormSet):
         This overrides the default Django version to add the ``childTypes`` data.
         """
         verbose_name = self.opts.verbose_name
-        return json.dumps({
-            'name': '#%s' % self.formset.prefix,
-            'options': {
-                'prefix': self.formset.prefix,
-                'addText': ugettext('Add another %(verbose_name)s') % {
-                    'verbose_name': capfirst(verbose_name),
-                },
-                'childTypes': [
+        return json.dumps(
             {
-                        'type': model._meta.model_name,
-                        'name': force_text(model._meta.verbose_name)
-                    } for model in self.formset.child_forms.keys()
-                ],
-                'deleteText': ugettext('Remove'),
+                "name": "#%s" % self.formset.prefix,
+                "options": {
+                    "prefix": self.formset.prefix,
+                    "addText": ugettext("Add another %(verbose_name)s")
+                    % {"verbose_name": capfirst(verbose_name)},
+                    "childTypes": [
+                        {
+                            "type": model._meta.model_name,
+                            "name": force_text(model._meta.verbose_name),
                         }
-        })
+                        for model in self.formset.child_forms.keys()
+                    ],
+                    "deleteText": ugettext("Remove"),
+                },
+            }
+        )
 
 
 class PolymorphicInlineSupportMixin(object):
@@ -119,14 +125,17 @@ class PolymorphicInlineSupportMixin(object):
     :class:`~django.contrib.admin.helpers.InlineAdminFormSet` for the polymorphic formsets.
     """
 
-    def get_inline_formsets(self, request, formsets, inline_instances, obj=None, *args, **kwargs):
+    def get_inline_formsets(
+        self, request, formsets, inline_instances, obj=None, *args, **kwargs
+    ):
         """
         Overwritten version to produce the proper admin wrapping for the
         polymorphic inline formset. This fixes the media and form appearance
         of the inline polymorphic models.
         """
-        inline_admin_formsets = super(PolymorphicInlineSupportMixin, self).get_inline_formsets(
-            request, formsets, inline_instances, obj=obj)
+        inline_admin_formsets = super(
+            PolymorphicInlineSupportMixin, self
+        ).get_inline_formsets(request, formsets, inline_instances, obj=obj)
 
         for admin_formset in inline_admin_formsets:
             if isinstance(admin_formset.formset, BasePolymorphicModelFormSet):

polymorphic/admin/inlines.py

@@ -10,9 +10,14 @@ from django.contrib.admin.utils import flatten_fieldsets
 from django.core.exceptions import ImproperlyConfigured
 from django.forms import Media
 
-from polymorphic.formsets import polymorphic_child_forms_factory, BasePolymorphicInlineFormSet, \
-    PolymorphicFormSetChild, UnsupportedChildType
+from polymorphic.formsets import (
+    BasePolymorphicInlineFormSet,
+    PolymorphicFormSetChild,
+    UnsupportedChildType,
+    polymorphic_child_forms_factory,
+)
 from polymorphic.formsets.utils import add_media
+
 from .helpers import PolymorphicInlineSupportMixin
 
 
@@ -31,14 +36,8 @@ class PolymorphicInlineModelAdmin(InlineModelAdmin):
     #: The extra media to add for the polymorphic inlines effect.
     #: This can be redefined for subclasses.
     polymorphic_media = Media(
-        js=(
-            'polymorphic/js/polymorphic_inlines.js',
-        ),
-        css={
-            'all': (
-                'polymorphic/css/polymorphic_inlines.css',
-            )
-        }
+        js=("polymorphic/js/polymorphic_inlines.js",),
+        css={"all": ("polymorphic/css/polymorphic_inlines.css",)},
     )
 
     #: The extra forms to show
@@ -90,7 +89,9 @@ class PolymorphicInlineModelAdmin(InlineModelAdmin):
         try:
             return self._child_inlines_lookup[model]
         except KeyError:
-            raise UnsupportedChildType("Model '{0}' not found in child_inlines".format(model.__name__))
+            raise UnsupportedChildType(
+                "Model '{0}' not found in child_inlines".format(model.__name__)
+            )
 
     def get_formset(self, request, obj=None, **kwargs):
         """
@@ -101,7 +102,9 @@ class PolymorphicInlineModelAdmin(InlineModelAdmin):
         :rtype: type
         """
         # Construct the FormSet class
-        FormSet = super(PolymorphicInlineModelAdmin, self).get_formset(request, obj=obj, **kwargs)
+        FormSet = super(PolymorphicInlineModelAdmin, self).get_formset(
+            request, obj=obj, **kwargs
+        )
 
         # Instead of completely redefining super().get_formset(), we use
         # the regular inlineformset_factory(), and amend that with our extra bits.
@@ -151,7 +154,10 @@ class PolymorphicInlineModelAdmin(InlineModelAdmin):
             child_media = child_instance.media
 
             # Avoid adding the same media object again and again
-            if child_media._css != base_media._css and child_media._js != base_media._js:
+            if (
+                child_media._css != base_media._css
+                and child_media._js != base_media._js
+            ):
                 add_media(all_media, child_media)
 
         add_media(all_media, self.polymorphic_media)
@@ -170,12 +176,15 @@ class PolymorphicInlineModelAdmin(InlineModelAdmin):
 
         The model form options however, will all be read.
         """
+
         formset_child = PolymorphicFormSetChild
         extra = 0  # TODO: currently unused for the children.
 
         def __init__(self, parent_inline):
             self.parent_inline = parent_inline
-            super(PolymorphicInlineModelAdmin.Child, self).__init__(parent_inline.parent_model, parent_inline.admin_site)
+            super(PolymorphicInlineModelAdmin.Child, self).__init__(
+                parent_inline.parent_model, parent_inline.admin_site
+            )
 
         def get_formset(self, request, obj=None, **kwargs):
             # The child inline is only used to construct the form,
@@ -209,8 +218,8 @@ class PolymorphicInlineModelAdmin(InlineModelAdmin):
             #
             # Transfer the local inline attributes to the formset child,
             # this allows overriding settings.
-            if 'fields' in kwargs:
-                fields = kwargs.pop('fields')
+            if "fields" in kwargs:
+                fields = kwargs.pop("fields")
             else:
                 fields = flatten_fieldsets(self.get_fieldsets(request, obj))
 
@@ -220,9 +229,15 @@ class PolymorphicInlineModelAdmin(InlineModelAdmin):
                 exclude = list(self.exclude)
 
             exclude.extend(self.get_readonly_fields(request, obj))
-            exclude.append('polymorphic_ctype')  # Django 1.10 blocks it, as it's a readonly field.
+            exclude.append(
+                "polymorphic_ctype"
+            )  # Django 1.10 blocks it, as it's a readonly field.
 
-            if self.exclude is None and hasattr(self.form, '_meta') and self.form._meta.exclude:
+            if (
+                self.exclude is None
+                and hasattr(self.form, "_meta")
+                and self.form._meta.exclude
+            ):
                 # Take the custom ModelForm's Meta.exclude into account only if the
                 # InlineModelAdmin doesn't define its own.
                 exclude.extend(self.form._meta.exclude)
@@ -232,7 +247,9 @@ class PolymorphicInlineModelAdmin(InlineModelAdmin):
                 "form": self.form,
                 "fields": fields,
                 "exclude": exclude or None,
-                "formfield_callback": partial(self.formfield_for_dbfield, request=request),
+                "formfield_callback": partial(
+                    self.formfield_for_dbfield, request=request
+                ),
             }
             defaults.update(kwargs)
 
@@ -247,5 +264,6 @@ class StackedPolymorphicInline(PolymorphicInlineModelAdmin):
     Stacked inline for django-polymorphic models.
     Since tabular doesn't make much sense with changed fields, just offer this one.
     """
+
     #: The default template to use.
-    template = 'admin/polymorphic/edit_inline/stacked.html'
+    template = "admin/polymorphic/edit_inline/stacked.html"

polymorphic/admin/parentadmin.py

@@ -7,7 +7,7 @@ from django.contrib import admin
 from django.contrib.admin.helpers import AdminErrorList, AdminForm
 from django.contrib.admin.templatetags.admin_urls import add_preserved_filters
 from django.contrib.contenttypes.models import ContentType
-from django.core.exceptions import PermissionDenied, ImproperlyConfigured
+from django.core.exceptions import ImproperlyConfigured, PermissionDenied
 from django.db import models
 from django.http import Http404, HttpResponseRedirect
 from django.template.response import TemplateResponse
@@ -15,9 +15,10 @@ from django.utils.encoding import force_text
 from django.utils.http import urlencode
 from django.utils.safestring import mark_safe
 from django.utils.translation import ugettext_lazy as _
-from polymorphic.utils import get_base_polymorphic_model
-from .forms import PolymorphicModelChoiceForm
 
+from polymorphic.utils import get_base_polymorphic_model
+
+from .forms import PolymorphicModelChoiceForm
 
 try:
     # Django 2.0+
@@ -73,7 +74,9 @@ class PolymorphicParentModelAdmin(admin.ModelAdmin):
     pk_regex = r"(\d+|__fk__)"
 
     def __init__(self, model, admin_site, *args, **kwargs):
-        super(PolymorphicParentModelAdmin, self).__init__(model, admin_site, *args, **kwargs)
+        super(PolymorphicParentModelAdmin, self).__init__(
+            model, admin_site, *args, **kwargs
+        )
         self._is_setup = False
 
         if self.base_model is None:
@@ -105,12 +108,22 @@ class PolymorphicParentModelAdmin(admin.ModelAdmin):
         # After the get_urls() is called, the URLs of the child model can't be exposed anymore to the Django URLconf,
         # which also means that a "Save and continue editing" button won't work.
         if self._is_setup:
-            raise RegistrationClosed("The admin model can't be registered anymore at this point.")
+            raise RegistrationClosed(
+                "The admin model can't be registered anymore at this point."
+            )
 
         if not issubclass(model, self.base_model):
-            raise TypeError("{0} should be a subclass of {1}".format(model.__name__, self.base_model.__name__))
+            raise TypeError(
+                "{0} should be a subclass of {1}".format(
+                    model.__name__, self.base_model.__name__
+                )
+            )
         if not issubclass(model_admin, admin.ModelAdmin):
-            raise TypeError("{0} should be a subclass of {1}".format(model_admin.__name__, admin.ModelAdmin.__name__))
+            raise TypeError(
+                "{0} should be a subclass of {1}".format(
+                    model_admin.__name__, admin.ModelAdmin.__name__
+                )
+            )
 
         self._child_admin_site.register(model, model_admin)
 
@@ -134,7 +147,7 @@ class PolymorphicParentModelAdmin(admin.ModelAdmin):
         self._lazy_setup()
         choices = []
         for model in self.get_child_models():
-            perm_function_name = 'has_{0}_permission'.format(action)
+            perm_function_name = "has_{0}_permission".format(action)
             model_admin = self._get_real_admin_by_model(model)
             perm_function = getattr(model_admin, perm_function_name)
             if not perm_function(request):
@@ -145,11 +158,16 @@ class PolymorphicParentModelAdmin(admin.ModelAdmin):
 
     def _get_real_admin(self, object_id, super_if_self=True):
         try:
-            obj = self.model.objects.non_polymorphic() \
-                .values('polymorphic_ctype').get(pk=object_id)
+            obj = (
+                self.model.objects.non_polymorphic()
+                .values("polymorphic_ctype")
+                .get(pk=object_id)
+            )
         except self.model.DoesNotExist:
             raise Http404
-        return self._get_real_admin_by_ct(obj['polymorphic_ctype'], super_if_self=super_if_self)
+        return self._get_real_admin_by_ct(
+            obj["polymorphic_ctype"], super_if_self=super_if_self
+        )
 
     def _get_real_admin_by_ct(self, ct_id, super_if_self=True):
         try:
@@ -159,7 +177,9 @@ class PolymorphicParentModelAdmin(admin.ModelAdmin):
 
         model_class = ct.model_class()
         if not model_class:
-            raise Http404("No model found for '{0}.{1}'.".format(*ct.natural_key()))  # Handle model deletion
+            raise Http404(
+                "No model found for '{0}.{1}'.".format(*ct.natural_key())
+            )  # Handle model deletion
 
         return self._get_real_admin_by_model(model_class, super_if_self=super_if_self)
 
@@ -167,14 +187,22 @@ class PolymorphicParentModelAdmin(admin.ModelAdmin):
         # In case of a ?ct_id=### parameter, the view is already checked for permissions.
         # Hence, make sure this is a derived object, or risk exposing other admin interfaces.
         if model_class not in self._child_models:
-            raise PermissionDenied("Invalid model '{0}', it must be registered as child model.".format(model_class))
+            raise PermissionDenied(
+                "Invalid model '{0}', it must be registered as child model.".format(
+                    model_class
+                )
+            )
 
         try:
             # HACK: the only way to get the instance of an model admin,
             # is to read the registry of the AdminSite.
             real_admin = self._child_admin_site._registry[model_class]
         except KeyError:
-            raise ChildAdminNotRegistered("No child admin site was registered for a '{0}' model.".format(model_class))
+            raise ChildAdminNotRegistered(
+                "No child admin site was registered for a '{0}' model.".format(
+                    model_class
+                )
+            )
 
         if super_if_self and real_admin is self:
             return super(PolymorphicParentModelAdmin, self)
@@ -188,19 +216,21 @@ class PolymorphicParentModelAdmin(admin.ModelAdmin):
             qs = qs.non_polymorphic()
         return qs
 
-    def add_view(self, request, form_url='', extra_context=None):
+    def add_view(self, request, form_url="", extra_context=None):
         """Redirect the add view to the real admin."""
-        ct_id = int(request.GET.get('ct_id', 0))
+        ct_id = int(request.GET.get("ct_id", 0))
         if not ct_id:
             # Display choices
             return self.add_type_view(request)
         else:
             real_admin = self._get_real_admin_by_ct(ct_id)
             # rebuild form_url, otherwise libraries below will override it.
-            form_url = add_preserved_filters({
-                'preserved_filters': urlencode({'ct_id': ct_id}),
-                'opts': self.model._meta},
-                form_url
+            form_url = add_preserved_filters(
+                {
+                    "preserved_filters": urlencode({"ct_id": ct_id}),
+                    "opts": self.model._meta,
+                },
+                form_url,
             )
             return real_admin.add_view(request, form_url, extra_context)
 
@@ -218,7 +248,9 @@ class PolymorphicParentModelAdmin(admin.ModelAdmin):
             return real_admin.changeform_view(request, object_id, *args, **kwargs)
         else:
             # Add view. As it should already be handled via `add_view`, this means something custom is done here!
-            return super(PolymorphicParentModelAdmin, self).changeform_view(request, object_id, *args, **kwargs)
+            return super(PolymorphicParentModelAdmin, self).changeform_view(
+                request, object_id, *args, **kwargs
+            )
 
     def history_view(self, request, object_id, extra_context=None):
         """Redirect the history view to the real admin."""
@@ -231,14 +263,14 @@ class PolymorphicParentModelAdmin(admin.ModelAdmin):
         return real_admin.delete_view(request, object_id, extra_context)
 
     def get_preserved_filters(self, request):
-        if '_changelist_filters' in request.GET:
+        if "_changelist_filters" in request.GET:
             request.GET = request.GET.copy()
-            filters = request.GET.get('_changelist_filters')
+            filters = request.GET.get("_changelist_filters")
             f = filters.split("&")
             for x in f:
-                c = x.split('=')
+                c = x.split("=")
                 request.GET[c[0]] = c[1]
-            del request.GET['_changelist_filters']
+            del request.GET["_changelist_filters"]
         return super(PolymorphicParentModelAdmin, self).get_preserved_filters(request)
 
     def get_urls(self):
@@ -256,91 +288,100 @@ class PolymorphicParentModelAdmin(admin.ModelAdmin):
         """
         Forward any request to a custom view of the real admin.
         """
-        ct_id = int(request.GET.get('ct_id', 0))
+        ct_id = int(request.GET.get("ct_id", 0))
         if not ct_id:
             # See if the path started with an ID.
             try:
-                pos = path.find('/')
+                pos = path.find("/")
                 if pos == -1:
                     object_id = long(path)
                 else:
                     object_id = long(path[0:pos])
             except ValueError:
-                raise Http404("No ct_id parameter, unable to find admin subclass for path '{0}'.".format(path))
+                raise Http404(
+                    "No ct_id parameter, unable to find admin subclass for path '{0}'.".format(
+                        path
+                    )
+                )
 
-            ct_id = self.model.objects.values_list('polymorphic_ctype_id', flat=True).get(pk=object_id)
+            ct_id = self.model.objects.values_list(
+                "polymorphic_ctype_id", flat=True
+            ).get(pk=object_id)
 
         real_admin = self._get_real_admin_by_ct(ct_id)
-        resolver = URLResolver('^', real_admin.urls)
+        resolver = URLResolver("^", real_admin.urls)
         resolvermatch = resolver.resolve(path)  # May raise Resolver404
         if not resolvermatch:
             raise Http404("No match for path '{0}' in admin subclass.".format(path))
 
         return resolvermatch.func(request, *resolvermatch.args, **resolvermatch.kwargs)
 
-    def add_type_view(self, request, form_url=''):
+    def add_type_view(self, request, form_url=""):
         """
         Display a choice form to select which page type to add.
         """
         if not self.has_add_permission(request):
             raise PermissionDenied
 
-        extra_qs = ''
-        if request.META['QUERY_STRING']:
+        extra_qs = ""
+        if request.META["QUERY_STRING"]:
             # QUERY_STRING is bytes in Python 3, using force_text() to decode it as string.
             # See QueryDict how Django deals with that.
-            extra_qs = '&{0}'.format(force_text(request.META['QUERY_STRING']))
+            extra_qs = "&{0}".format(force_text(request.META["QUERY_STRING"]))
 
-        choices = self.get_child_type_choices(request, 'add')
+        choices = self.get_child_type_choices(request, "add")
         if len(choices) == 1:
-            return HttpResponseRedirect('?ct_id={0}{1}'.format(choices[0][0], extra_qs))
+            return HttpResponseRedirect("?ct_id={0}{1}".format(choices[0][0], extra_qs))
 
         # Create form
         form = self.add_type_form(
-            data=request.POST if request.method == 'POST' else None,
-            initial={'ct_id': choices[0][0]}
+            data=request.POST if request.method == "POST" else None,
+            initial={"ct_id": choices[0][0]},
         )
-        form.fields['ct_id'].choices = choices
+        form.fields["ct_id"].choices = choices
 
         if form.is_valid():
-            return HttpResponseRedirect('?ct_id={0}{1}'.format(form.cleaned_data['ct_id'], extra_qs))
+            return HttpResponseRedirect(
+                "?ct_id={0}{1}".format(form.cleaned_data["ct_id"], extra_qs)
+            )
 
         # Wrap in all admin layout
-        fieldsets = ((None, {'fields': ('ct_id',)}),)
+        fieldsets = ((None, {"fields": ("ct_id",)}),)
         adminForm = AdminForm(form, fieldsets, {}, model_admin=self)
         media = self.media + adminForm.media
         opts = self.model._meta
 
         context = {
-            'title': _('Add %s') % force_text(opts.verbose_name),
-            'adminform': adminForm,
-            'is_popup': ("_popup" in request.POST or
-                         "_popup" in request.GET),
-            'media': mark_safe(media),
-            'errors': AdminErrorList(form, ()),
-            'app_label': opts.app_label,
+            "title": _("Add %s") % force_text(opts.verbose_name),
+            "adminform": adminForm,
+            "is_popup": ("_popup" in request.POST or "_popup" in request.GET),
+            "media": mark_safe(media),
+            "errors": AdminErrorList(form, ()),
+            "app_label": opts.app_label,
         }
         return self.render_add_type_form(request, context, form_url)
 
-    def render_add_type_form(self, request, context, form_url=''):
+    def render_add_type_form(self, request, context, form_url=""):
         """
         Render the page type choice form.
         """
         opts = self.model._meta
         app_label = opts.app_label
-        context.update({
-            'has_change_permission': self.has_change_permission(request),
-            'form_url': mark_safe(form_url),
-            'opts': opts,
-            'add': True,
-            'save_on_top': self.save_on_top,
-        })
+        context.update(
+            {
+                "has_change_permission": self.has_change_permission(request),
+                "form_url": mark_safe(form_url),
+                "opts": opts,
+                "add": True,
+                "save_on_top": self.save_on_top,
+            }
+        )
 
         templates = self.add_type_template or [
             "admin/%s/%s/add_type_form.html" % (app_label, opts.object_name.lower()),
             "admin/%s/add_type_form.html" % app_label,
             "admin/polymorphic/add_type_form.html",  # added default here
-            "admin/add_type_form.html"
+            "admin/add_type_form.html",
         ]
 
         request.current_app = self.admin_site.name
@@ -359,7 +400,8 @@ class PolymorphicParentModelAdmin(admin.ModelAdmin):
             "admin/%s/%s/change_list.html" % (app_label, opts.object_name.lower()),
             "admin/%s/change_list.html" % app_label,
             # Added base class:
-            "admin/%s/%s/change_list.html" % (base_app_label, base_opts.object_name.lower()),
+            "admin/%s/%s/change_list.html"
+            % (base_app_label, base_opts.object_name.lower()),
             "admin/%s/change_list.html" % base_app_label,
-            "admin/change_list.html"
+            "admin/change_list.html",
         ]

polymorphic/base.py

@@ -20,9 +20,11 @@ from .query import PolymorphicQuerySet
 
 # PolymorphicQuerySet Q objects (and filter()) support these additional key words.
 # These are forbidden as field names (a descriptive exception is raised)
-POLYMORPHIC_SPECIAL_Q_KWORDS = ['instance_of', 'not_instance_of']
+POLYMORPHIC_SPECIAL_Q_KWORDS = ["instance_of", "not_instance_of"]
 
-DUMPDATA_COMMAND = os.path.join('django', 'core', 'management', 'commands', 'dumpdata.py')
+DUMPDATA_COMMAND = os.path.join(
+    "django", "core", "management", "commands", "dumpdata.py"
+)
 
 
 class ManagerInheritanceWarning(RuntimeWarning):
@@ -32,6 +34,7 @@ class ManagerInheritanceWarning(RuntimeWarning):
 ###################################################################################
 # PolymorphicModel meta class
 
+
 class PolymorphicModelBase(ModelBase):
     """
     Manager inheritance is a pretty complex topic which may need
@@ -60,17 +63,21 @@ class PolymorphicModelBase(ModelBase):
         # print; print '###', model_name, '- bases:', bases
 
         # Workaround compatibility issue with six.with_metaclass() and custom Django model metaclasses:
-        if not attrs and model_name == 'NewBase':
-            return super(PolymorphicModelBase, self).__new__(self, model_name, bases, attrs)
+        if not attrs and model_name == "NewBase":
+            return super(PolymorphicModelBase, self).__new__(
+                self, model_name, bases, attrs
+            )
 
         # Make sure that manager_inheritance_from_future is set, since django-polymorphic 1.x already
         # simulated that behavior on the polymorphic manager to all subclasses behave like polymorphics
         if django.VERSION < (2, 0):
-            if 'Meta' in attrs:
-                if not hasattr(attrs['Meta'], 'manager_inheritance_from_future'):
-                    attrs['Meta'].manager_inheritance_from_future = True
+            if "Meta" in attrs:
+                if not hasattr(attrs["Meta"], "manager_inheritance_from_future"):
+                    attrs["Meta"].manager_inheritance_from_future = True
             else:
-                attrs['Meta'] = type('Meta', (object,), {'manager_inheritance_from_future': True})
+                attrs["Meta"] = type(
+                    "Meta", (object,), {"manager_inheritance_from_future": True}
+                )
 
         # create new model
         new_class = self.call_superclass_new_method(model_name, bases, attrs)
@@ -103,17 +110,21 @@ class PolymorphicModelBase(ModelBase):
         # We run into this problem if polymorphic.py is located in a top-level directory
         # which is directly in the python path. To work around this we temporarily set
         # app_label here for PolymorphicModel.
-        meta = attrs.get('Meta', None)
-        do_app_label_workaround = (meta
-                                   and attrs['__module__'] == 'polymorphic'
-                                   and model_name == 'PolymorphicModel'
-                                   and getattr(meta, 'app_label', None) is None)
+        meta = attrs.get("Meta", None)
+        do_app_label_workaround = (
+            meta
+            and attrs["__module__"] == "polymorphic"
+            and model_name == "PolymorphicModel"
+            and getattr(meta, "app_label", None) is None
+        )
 
         if do_app_label_workaround:
-            meta.app_label = 'poly_dummy_app_label'
-        new_class = super(PolymorphicModelBase, self).__new__(self, model_name, bases, attrs)
+            meta.app_label = "poly_dummy_app_label"
+        new_class = super(PolymorphicModelBase, self).__new__(
+            self, model_name, bases, attrs
+        )
         if do_app_label_workaround:
-            del(meta.app_label)
+            del meta.app_label
         return new_class
 
     @classmethod
@@ -133,17 +144,25 @@ class PolymorphicModelBase(ModelBase):
             if django.VERSION < (2, 0):
                 extra = "\nConsider using Meta.manager_inheritance_from_future = True for Django 1.x projects"
             else:
-                extra = ''
-            e = ('PolymorphicModel: "{0}.{1}" manager is of type "{2}", but must be a subclass of'
-                 ' PolymorphicManager.{extra} to support retrieving subclasses'.format(
-                model_name, manager_name, type(manager).__name__, extra=extra))
+                extra = ""
+            e = (
+                'PolymorphicModel: "{0}.{1}" manager is of type "{2}", but must be a subclass of'
+                " PolymorphicManager.{extra} to support retrieving subclasses".format(
+                    model_name, manager_name, type(manager).__name__, extra=extra
+                )
+            )
             warnings.warn(e, ManagerInheritanceWarning, stacklevel=3)
             return manager
 
-        if not getattr(manager, 'queryset_class', None) or not issubclass(manager.queryset_class, PolymorphicQuerySet):
-            e = ('PolymorphicModel: "{0}.{1}" has been instantiated with a queryset class '
-                 'which is not a subclass of PolymorphicQuerySet (which is required)'.format(
-                model_name, manager_name))
+        if not getattr(manager, "queryset_class", None) or not issubclass(
+            manager.queryset_class, PolymorphicQuerySet
+        ):
+            e = (
+                'PolymorphicModel: "{0}.{1}" has been instantiated with a queryset class '
+                "which is not a subclass of PolymorphicQuerySet (which is required)".format(
+                    model_name, manager_name
+                )
+            )
             warnings.warn(e, ManagerInheritanceWarning, stacklevel=3)
         return manager
 
@@ -151,8 +170,12 @@ class PolymorphicModelBase(ModelBase):
     def base_objects(self):
         warnings.warn(
             "Using PolymorphicModel.base_objects is deprecated.\n"
-            "Use {0}.objects.non_polymorphic() instead.".format(self.__class__.__name__),
-            DeprecationWarning, stacklevel=2)
+            "Use {0}.objects.non_polymorphic() instead.".format(
+                self.__class__.__name__
+            ),
+            DeprecationWarning,
+            stacklevel=2,
+        )
         return self._base_objects
 
     @property
@@ -162,13 +185,13 @@ class PolymorphicModelBase(ModelBase):
         # manager as default manager for the third level of inheritance when
         # that third level doesn't define a manager at all.
         manager = models.Manager()
-        manager.name = 'base_objects'
+        manager.name = "base_objects"
         manager.model = self
         return manager
 
     @property
     def _default_manager(self):
-        if len(sys.argv) > 1 and sys.argv[1] == 'dumpdata':
+        if len(sys.argv) > 1 and sys.argv[1] == "dumpdata":
             # TODO: investigate Django how this can be avoided
             # hack: a small patch to Django would be a better solution.
             # Django's management command 'dumpdata' relies on non-polymorphic
@@ -178,14 +201,19 @@ class PolymorphicModelBase(ModelBase):
             # (non-polymorphic default manager is 'base_objects' for polymorphic models).
             # This way we don't need to patch django.core.management.commands.dumpdata
             # for all supported Django versions.
-            frm = inspect.stack()[1]  # frm[1] is caller file name, frm[3] is caller function name
+            frm = inspect.stack()[
+                1
+            ]  # frm[1] is caller file name, frm[3] is caller function name
             if DUMPDATA_COMMAND in frm[1]:
                 return self._base_objects
 
         manager = super(PolymorphicModelBase, self)._default_manager
         if not isinstance(manager, PolymorphicManager):
-            warnings.warn("{0}._default_manager is not a PolymorphicManager".format(
+            warnings.warn(
+                "{0}._default_manager is not a PolymorphicManager".format(
                     self.__class__.__name__
-            ), ManagerInheritanceWarning)
+                ),
+                ManagerInheritanceWarning,
+            )
 
         return manager

polymorphic/compat.py

@@ -1,21 +1,20 @@
 """Compatibility with Python 2 (taken from 'django.utils.six')"""
 import sys
 
-
 PY2 = sys.version_info[0] == 2
 PY3 = sys.version_info[0] == 3
 
 
 if PY3:
-    string_types = str,
-    integer_types = int,
-    class_types = type,
+    string_types = (str,)
+    integer_types = (int,)
+    class_types = (type,)
     text_type = str
     binary_type = bytes
 
     MAXSIZE = sys.maxsize
 else:
-    string_types = basestring,
+    string_types = (basestring,)
     integer_types = (int, long)
 
 
@@ -23,7 +22,8 @@ def with_metaclass(meta, *bases):
     class metaclass(type):
         def __new__(cls, name, this_bases, d):
             return meta(name, bases, d)
-    return type.__new__(metaclass, 'temporary_class', (), {})
+
+    return type.__new__(metaclass, "temporary_class", (), {})
 
 
 def python_2_unicode_compatible(klass):
@@ -35,10 +35,11 @@ def python_2_unicode_compatible(klass):
     returning text and apply this decorator to the class.
     """
     if PY2:
-        if '__str__' not in klass.__dict__:
-            raise ValueError("@python_2_unicode_compatible cannot be applied "
-                             "to %s because it doesn't define __str__()." %
-                             klass.__name__)
+        if "__str__" not in klass.__dict__:
+            raise ValueError(
+                "@python_2_unicode_compatible cannot be applied "
+                "to %s because it doesn't define __str__()." % klass.__name__
+            )
         klass.__unicode__ = klass.__str__
-        klass.__str__ = lambda self: self.__unicode__().encode('utf-8')
+        klass.__str__ = lambda self: self.__unicode__().encode("utf-8")
     return klass

polymorphic/contrib/extra_views.py

@@ -5,15 +5,20 @@ The ``extra_views.advanced`` provides a method to combine that with a create/upd
 This package provides classes that support both options for polymorphic formsets.
 """
 from __future__ import absolute_import
-from django.core.exceptions import ImproperlyConfigured
-import extra_views
-from polymorphic.formsets import polymorphic_child_forms_factory, BasePolymorphicModelFormSet, BasePolymorphicInlineFormSet
 
+import extra_views
+from django.core.exceptions import ImproperlyConfigured
+
+from polymorphic.formsets import (
+    BasePolymorphicInlineFormSet,
+    BasePolymorphicModelFormSet,
+    polymorphic_child_forms_factory,
+)
 
 __all__ = (
-    'PolymorphicFormSetView',
-    'PolymorphicInlineFormSetView',
-    'PolymorphicInlineFormSet',
+    "PolymorphicFormSetView",
+    "PolymorphicInlineFormSetView",
+    "PolymorphicInlineFormSet",
 )
 
 
@@ -25,7 +30,7 @@ class PolymorphicFormSetMixin(object):
     formset_class = BasePolymorphicModelFormSet
 
     #: Default 0 extra forms
-    factory_kwargs = {'extra': 0}
+    factory_kwargs = {"extra": 0}
 
     #: Define the children
     # :type: list[PolymorphicFormSetChild]
@@ -36,7 +41,9 @@ class PolymorphicFormSetMixin(object):
         :rtype: list[PolymorphicFormSetChild]
         """
         if not self.formset_children:
-            raise ImproperlyConfigured("Define 'formset_children' as list of `PolymorphicFormSetChild`")
+            raise ImproperlyConfigured(
+                "Define 'formset_children' as list of `PolymorphicFormSetChild`"
+            )
         return self.formset_children
 
     def get_formset_child_kwargs(self):
@@ -51,7 +58,9 @@ class PolymorphicFormSetMixin(object):
         # reuse the standard factories, and then add `child_forms`, the same can be done here.
         # This makes sure the base class construction is completely honored.
         FormSet = super(PolymorphicFormSetMixin, self).get_formset()
-        FormSet.child_forms = polymorphic_child_forms_factory(self.get_formset_children(), **self.get_formset_child_kwargs())
+        FormSet.child_forms = polymorphic_child_forms_factory(
+            self.get_formset_children(), **self.get_formset_child_kwargs()
+        )
         return FormSet
 
 
@@ -72,10 +81,13 @@ class PolymorphicFormSetView(PolymorphicFormSetMixin, extra_views.ModelFormSetVi
             ]
 
     """
+
     formset_class = BasePolymorphicModelFormSet
 
 
-class PolymorphicInlineFormSetView(PolymorphicFormSetMixin, extra_views.InlineFormSetView):
+class PolymorphicInlineFormSetView(
+    PolymorphicFormSetMixin, extra_views.InlineFormSetView
+):
     """
     A view that displays a single polymorphic formset - with one parent object.
     This is a variation of the :mod:`extra_views` package classes for django-polymorphic.
@@ -93,10 +105,13 @@ class PolymorphicInlineFormSetView(PolymorphicFormSetMixin, extra_views.InlineFo
                 PolymorphicFormSetChild(ItemSubclass2),
             ]
     """
+
     formset_class = BasePolymorphicInlineFormSet
 
 
-class PolymorphicInlineFormSet(PolymorphicFormSetMixin, extra_views.InlineFormSetFactory):
+class PolymorphicInlineFormSet(
+    PolymorphicFormSetMixin, extra_views.InlineFormSetFactory
+):
     """
     An inline to add to the ``inlines`` of
     the :class:`~extra_views.advanced.CreateWithInlinesView`
@@ -123,4 +138,5 @@ class PolymorphicInlineFormSet(PolymorphicFormSetMixin, extra_views.InlineFormSe
                 return self.object.get_absolute_url()
 
     """
+
     formset_class = BasePolymorphicInlineFormSet

polymorphic/contrib/guardian.py

@@ -10,7 +10,7 @@ def get_polymorphic_base_content_type(obj):
 
     https://django-guardian.readthedocs.io/en/latest/configuration.html#guardian-get-content-type
     """
-    if hasattr(obj, 'polymorphic_model_marker'):
+    if hasattr(obj, "polymorphic_model_marker"):
         try:
             superclasses = list(obj.__class__.mro())
         except TypeError:
@@ -19,11 +19,11 @@ def get_polymorphic_base_content_type(obj):
 
         polymorphic_superclasses = list()
         for sclass in superclasses:
-            if hasattr(sclass, 'polymorphic_model_marker'):
+            if hasattr(sclass, "polymorphic_model_marker"):
                 polymorphic_superclasses.append(sclass)
 
         # PolymorphicMPTT adds an additional class between polymorphic and base class.
-        if hasattr(obj, 'can_have_children'):
+        if hasattr(obj, "can_have_children"):
             root_polymorphic_class = polymorphic_superclasses[-3]
         else:
             root_polymorphic_class = polymorphic_superclasses[-2]

polymorphic/formsets/__init__.py

@@ -8,31 +8,30 @@ For every child type, there is an :class:`PolymorphicFormSetChild` instance
 that describes how to display and construct the child.
 It's parameters are very similar to the parent's factory method.
 """
-from .models import (
-    BasePolymorphicModelFormSet,
-    BasePolymorphicInlineFormSet,
-    PolymorphicFormSetChild,
-    UnsupportedChildType,
-    polymorphic_modelformset_factory,
-    polymorphic_inlineformset_factory,
-    polymorphic_child_forms_factory,
-)
-from .generic import (
-    # Can import generic here, as polymorphic already depends on the 'contenttypes' app.
+from .generic import (  # Can import generic here, as polymorphic already depends on the 'contenttypes' app.
     BaseGenericPolymorphicInlineFormSet,
     GenericPolymorphicFormSetChild,
     generic_polymorphic_inlineformset_factory,
 )
+from .models import (
+    BasePolymorphicInlineFormSet,
+    BasePolymorphicModelFormSet,
+    PolymorphicFormSetChild,
+    UnsupportedChildType,
+    polymorphic_child_forms_factory,
+    polymorphic_inlineformset_factory,
+    polymorphic_modelformset_factory,
+)
 
 __all__ = (
-    'BasePolymorphicModelFormSet',
-    'BasePolymorphicInlineFormSet',
-    'PolymorphicFormSetChild',
-    'UnsupportedChildType',
-    'polymorphic_modelformset_factory',
-    'polymorphic_inlineformset_factory',
-    'polymorphic_child_forms_factory',
-    'BaseGenericPolymorphicInlineFormSet',
-    'GenericPolymorphicFormSetChild',
-    'generic_polymorphic_inlineformset_factory',
+    "BasePolymorphicModelFormSet",
+    "BasePolymorphicInlineFormSet",
+    "PolymorphicFormSetChild",
+    "UnsupportedChildType",
+    "polymorphic_modelformset_factory",
+    "polymorphic_inlineformset_factory",
+    "polymorphic_child_forms_factory",
+    "BaseGenericPolymorphicInlineFormSet",
+    "GenericPolymorphicFormSetChild",
+    "generic_polymorphic_inlineformset_factory",
 )

polymorphic/formsets/generic.py

@@ -1,9 +1,16 @@
-from django.contrib.contenttypes.forms import BaseGenericInlineFormSet, generic_inlineformset_factory
+from django.contrib.contenttypes.forms import (
+    BaseGenericInlineFormSet,
+    generic_inlineformset_factory,
+)
 from django.contrib.contenttypes.models import ContentType
 from django.db import models
 from django.forms.models import ModelForm
 
-from .models import BasePolymorphicModelFormSet, polymorphic_child_forms_factory, PolymorphicFormSetChild
+from .models import (
+    BasePolymorphicModelFormSet,
+    PolymorphicFormSetChild,
+    polymorphic_child_forms_factory,
+)
 
 
 class GenericPolymorphicFormSetChild(PolymorphicFormSetChild):
@@ -12,8 +19,8 @@ class GenericPolymorphicFormSetChild(PolymorphicFormSetChild):
     """
 
     def __init__(self, *args, **kwargs):
-        self.ct_field = kwargs.pop('ct_field', 'content_type')
-        self.fk_field = kwargs.pop('fk_field', 'object_id')
+        self.ct_field = kwargs.pop("ct_field", "content_type")
+        self.fk_field = kwargs.pop("fk_field", "object_id")
         super(GenericPolymorphicFormSetChild, self).__init__(*args, **kwargs)
 
     def get_form(self, ct_field="content_type", fk_field="object_id", **kwargs):
@@ -21,7 +28,7 @@ class GenericPolymorphicFormSetChild(PolymorphicFormSetChild):
         Construct the form class for the formset child.
         """
         exclude = list(self.exclude)
-        extra_exclude = kwargs.pop('extra_exclude', None)
+        extra_exclude = kwargs.pop("extra_exclude", None)
         if extra_exclude:
             exclude += list(extra_exclude)
 
@@ -31,33 +38,52 @@ class GenericPolymorphicFormSetChild(PolymorphicFormSetChild):
         opts = self.model._meta
         ct_field = opts.get_field(self.ct_field)
 
-        if not isinstance(ct_field, models.ForeignKey) or ct_field.remote_field.model != ContentType:
-            raise Exception("fk_name '%s' is not a ForeignKey to ContentType" % ct_field)
+        if (
+            not isinstance(ct_field, models.ForeignKey)
+            or ct_field.remote_field.model != ContentType
+        ):
+            raise Exception(
+                "fk_name '%s' is not a ForeignKey to ContentType" % ct_field
+            )
 
         fk_field = opts.get_field(self.fk_field)  # let the exception propagate
         exclude.extend([ct_field.name, fk_field.name])
-        kwargs['exclude'] = exclude
+        kwargs["exclude"] = exclude
 
         return super(GenericPolymorphicFormSetChild, self).get_form(**kwargs)
 
 
-class BaseGenericPolymorphicInlineFormSet(BaseGenericInlineFormSet, BasePolymorphicModelFormSet):
+class BaseGenericPolymorphicInlineFormSet(
+    BaseGenericInlineFormSet, BasePolymorphicModelFormSet
+):
     """
     Polymorphic formset variation for inline generic formsets
     """
 
 
-def generic_polymorphic_inlineformset_factory(model, formset_children, form=ModelForm,
+def generic_polymorphic_inlineformset_factory(
+    model,
+    formset_children,
+    form=ModelForm,
     formset=BaseGenericPolymorphicInlineFormSet,
-                                              ct_field="content_type", fk_field="object_id",
+    ct_field="content_type",
+    fk_field="object_id",
     # Base form
     # TODO: should these fields be removed in favor of creating
     # the base form as a formset child too?
-                                              fields=None, exclude=None,
-                                              extra=1, can_order=False, can_delete=True,
-                                              max_num=None, formfield_callback=None,
-                                              validate_max=False, for_concrete_model=True,
-                                              min_num=None, validate_min=False, child_form_kwargs=None):
+    fields=None,
+    exclude=None,
+    extra=1,
+    can_order=False,
+    can_delete=True,
+    max_num=None,
+    formfield_callback=None,
+    validate_max=False,
+    for_concrete_model=True,
+    min_num=None,
+    validate_min=False,
+    child_form_kwargs=None,
+):
     """
     Construct the class for a generic inline polymorphic formset.
 
@@ -70,22 +96,22 @@ def generic_polymorphic_inlineformset_factory(model, formset_children, form=Mode
     :rtype: type
     """
     kwargs = {
-        'model': model,
-        'form': form,
-        'formfield_callback': formfield_callback,
-        'formset': formset,
-        'ct_field': ct_field,
-        'fk_field': fk_field,
-        'extra': extra,
-        'can_delete': can_delete,
-        'can_order': can_order,
-        'fields': fields,
-        'exclude': exclude,
-        'min_num': min_num,
-        'max_num': max_num,
-        'validate_min': validate_min,
-        'validate_max': validate_max,
-        'for_concrete_model': for_concrete_model,
+        "model": model,
+        "form": form,
+        "formfield_callback": formfield_callback,
+        "formset": formset,
+        "ct_field": ct_field,
+        "fk_field": fk_field,
+        "extra": extra,
+        "can_delete": can_delete,
+        "can_order": can_order,
+        "fields": fields,
+        "exclude": exclude,
+        "min_num": min_num,
+        "max_num": max_num,
+        "validate_min": validate_min,
+        "validate_max": validate_max,
+        "for_concrete_model": for_concrete_model,
         # 'localized_fields': localized_fields,
         # 'labels': labels,
         # 'help_texts': help_texts,
@@ -97,12 +123,14 @@ def generic_polymorphic_inlineformset_factory(model, formset_children, form=Mode
 
     child_kwargs = {
         # 'exclude': exclude,
-        'ct_field': ct_field,
-        'fk_field': fk_field,
+        "ct_field": ct_field,
+        "fk_field": fk_field,
     }
     if child_form_kwargs:
         child_kwargs.update(child_form_kwargs)
 
     FormSet = generic_inlineformset_factory(**kwargs)
-    FormSet.child_forms = polymorphic_child_forms_factory(formset_children, **child_kwargs)
+    FormSet.child_forms = polymorphic_child_forms_factory(
+        formset_children, **child_kwargs
+    )
     return FormSet

polymorphic/formsets/models.py

@@ -3,10 +3,18 @@ from collections import OrderedDict
 from django import forms
 from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import ImproperlyConfigured, ValidationError
-from django.forms.models import ModelForm, BaseModelFormSet, BaseInlineFormSet, modelform_factory, modelformset_factory, inlineformset_factory
+from django.forms.models import (
+    BaseInlineFormSet,
+    BaseModelFormSet,
+    ModelForm,
+    inlineformset_factory,
+    modelform_factory,
+    modelformset_factory,
+)
 from django.utils.functional import cached_property
 
 from polymorphic.models import PolymorphicModel
+
 from .utils import add_media
 
 
@@ -20,9 +28,19 @@ class PolymorphicFormSetChild(object):
     Provide this information in the :func:'polymorphic_inlineformset_factory' construction.
     """
 
-    def __init__(self, model, form=ModelForm, fields=None, exclude=None,
-                 formfield_callback=None, widgets=None, localized_fields=None,
-                 labels=None, help_texts=None, error_messages=None):
+    def __init__(
+        self,
+        model,
+        form=ModelForm,
+        fields=None,
+        exclude=None,
+        formfield_callback=None,
+        widgets=None,
+        localized_fields=None,
+        labels=None,
+        help_texts=None,
+        error_messages=None,
+    ):
 
         self.model = model
 
@@ -59,20 +77,20 @@ class PolymorphicFormSetChild(object):
         # we allow to define things like 'extra_...' fields that are amended to the current child settings.
 
         exclude = list(self.exclude)
-        extra_exclude = kwargs.pop('extra_exclude', None)
+        extra_exclude = kwargs.pop("extra_exclude", None)
         if extra_exclude:
             exclude += list(extra_exclude)
 
         defaults = {
-            'form': self._form_base,
-            'formfield_callback': self.formfield_callback,
-            'fields': self.fields,
-            'exclude': exclude,
+            "form": self._form_base,
+            "formfield_callback": self.formfield_callback,
+            "fields": self.fields,
+            "exclude": exclude,
             # 'for_concrete_model': for_concrete_model,
-            'localized_fields': self.localized_fields,
-            'labels': self.labels,
-            'help_texts': self.help_texts,
-            'error_messages': self.error_messages,
+            "localized_fields": self.localized_fields,
+            "labels": self.labels,
+            "help_texts": self.help_texts,
+            "error_messages": self.error_messages,
             # 'field_classes': field_classes,
         }
         defaults.update(kwargs)
@@ -125,61 +143,71 @@ class BasePolymorphicModelFormSet(BaseModelFormSet):
             pk_field = self.model._meta.pk
             to_python = self._get_to_python(pk_field)
             pk = to_python(pk)
-            kwargs['instance'] = self._existing_object(pk)
-        if i < self.initial_form_count() and 'instance' not in kwargs:
-            kwargs['instance'] = self.get_queryset()[i]
+            kwargs["instance"] = self._existing_object(pk)
+        if i < self.initial_form_count() and "instance" not in kwargs:
+            kwargs["instance"] = self.get_queryset()[i]
         if i >= self.initial_form_count() and self.initial_extra:
             # Set initial values for extra forms
             try:
-                kwargs['initial'] = self.initial_extra[i - self.initial_form_count()]
+                kwargs["initial"] = self.initial_extra[i - self.initial_form_count()]
             except IndexError:
                 pass
 
         # BaseFormSet logic, with custom formset_class
         defaults = {
-            'auto_id': self.auto_id,
-            'prefix': self.add_prefix(i),
-            'error_class': self.error_class,
+            "auto_id": self.auto_id,
+            "prefix": self.add_prefix(i),
+            "error_class": self.error_class,
         }
         if self.is_bound:
-            defaults['data'] = self.data
-            defaults['files'] = self.files
-        if self.initial and 'initial' not in kwargs:
+            defaults["data"] = self.data
+            defaults["files"] = self.files
+        if self.initial and "initial" not in kwargs:
             try:
-                defaults['initial'] = self.initial[i]
+                defaults["initial"] = self.initial[i]
             except IndexError:
                 pass
         # Allow extra forms to be empty, unless they're part of
         # the minimum forms.
         if i >= self.initial_form_count() and i >= self.min_num:
-            defaults['empty_permitted'] = True
-            defaults['use_required_attribute'] = False
+            defaults["empty_permitted"] = True
+            defaults["use_required_attribute"] = False
         defaults.update(kwargs)
 
         # Need to find the model that will be displayed in this form.
         # Hence, peeking in the self.queryset_data beforehand.
         if self.is_bound:
-            if 'instance' in defaults:
+            if "instance" in defaults:
                 # Object is already bound to a model, won't change the content type
-                model = defaults['instance'].get_real_instance_class()  # allow proxy models
+                model = defaults[
+                    "instance"
+                ].get_real_instance_class()  # allow proxy models
             else:
                 # Extra or empty form, use the provided type.
                 # Note this completely tru
-                prefix = defaults['prefix']
+                prefix = defaults["prefix"]
                 try:
                     ct_id = int(self.data["{0}-polymorphic_ctype".format(prefix)])
                 except (KeyError, ValueError):
-                    raise ValidationError("Formset row {0} has no 'polymorphic_ctype' defined!".format(prefix))
+                    raise ValidationError(
+                        "Formset row {0} has no 'polymorphic_ctype' defined!".format(
+                            prefix
+                        )
+                    )
 
                 model = ContentType.objects.get_for_id(ct_id).model_class()
                 if model not in self.child_forms:
                     # Perform basic validation, as we skip the ChoiceField here.
-                    raise UnsupportedChildType("Child model type {0} is not part of the formset".format(model))
+                    raise UnsupportedChildType(
+                        "Child model type {0} is not part of the formset".format(model)
+                    )
         else:
-            if 'instance' in defaults:
-                model = defaults['instance'].get_real_instance_class()  # allow proxy models
-            elif 'polymorphic_ctype' in defaults.get('initial', {}):
-                model = defaults['initial']['polymorphic_ctype'].model_class()
+            if "instance" in defaults:
+                model = defaults[
+                    "instance"
+                ].get_real_instance_class()  # allow proxy models
+            elif "polymorphic_ctype" in defaults.get("initial", {}):
+                model = defaults["initial"]["polymorphic_ctype"].model_class()
             elif i < len(self.queryset_data):
                 model = self.queryset_data[i].__class__
             else:
@@ -196,9 +224,13 @@ class BasePolymorphicModelFormSet(BaseModelFormSet):
 
     def add_fields(self, form, index):
         """Add a hidden field for the content type."""
-        ct = ContentType.objects.get_for_model(form._meta.model, for_concrete_model=False)
+        ct = ContentType.objects.get_for_model(
+            form._meta.model, for_concrete_model=False
+        )
         choices = [(ct.pk, ct)]  # Single choice, existing forms can't change the value.
-        form.fields['polymorphic_ctype'] = forms.ChoiceField(choices=choices, initial=ct.pk, required=False, widget=forms.HiddenInput)
+        form.fields["polymorphic_ctype"] = forms.ChoiceField(
+            choices=choices, initial=ct.pk, required=False, widget=forms.HiddenInput
+        )
         super(BasePolymorphicModelFormSet, self).add_fields(form, index)
 
     def get_form_class(self, model):
@@ -206,7 +238,9 @@ class BasePolymorphicModelFormSet(BaseModelFormSet):
         Return the proper form class for the given model.
         """
         if not self.child_forms:
-            raise ImproperlyConfigured("No 'child_forms' defined in {0}".format(self.__class__.__name__))
+            raise ImproperlyConfigured(
+                "No 'child_forms' defined in {0}".format(self.__class__.__name__)
+            )
         if not issubclass(model, PolymorphicModel):
             raise TypeError("Expect polymorphic model type, not {0}".format(model))
 
@@ -218,7 +252,8 @@ class BasePolymorphicModelFormSet(BaseModelFormSet):
                 "The '{0}' found a '{1}' model in the queryset, "
                 "but no form class is registered to display it.".format(
                     self.__class__.__name__, model.__name__
-                ))
+                )
+            )
 
     def is_multipart(self):
         """
@@ -247,7 +282,7 @@ class BasePolymorphicModelFormSet(BaseModelFormSet):
 
             form = form_class(
                 auto_id=self.auto_id,
-                prefix=self.add_prefix('__prefix__'),
+                prefix=self.add_prefix("__prefix__"),
                 empty_permitted=True,
                 use_required_attribute=False,
                 **kwargs
@@ -259,20 +294,37 @@ class BasePolymorphicModelFormSet(BaseModelFormSet):
     @property
     def empty_form(self):
         # TODO: make an exception when can_add_base is defined?
-        raise RuntimeError("'empty_form' is not used in polymorphic formsets, use 'empty_forms' instead.")
+        raise RuntimeError(
+            "'empty_form' is not used in polymorphic formsets, use 'empty_forms' instead."
+        )
 
 
-def polymorphic_modelformset_factory(model, formset_children,
+def polymorphic_modelformset_factory(
+    model,
+    formset_children,
     formset=BasePolymorphicModelFormSet,
     # Base field
     # TODO: should these fields be removed in favor of creating
     # the base form as a formset child too?
     form=ModelForm,
-                                     fields=None, exclude=None, extra=1, can_order=False,
-                                     can_delete=True, max_num=None, formfield_callback=None,
-                                     widgets=None, validate_max=False, localized_fields=None,
-                                     labels=None, help_texts=None, error_messages=None,
-                                     min_num=None, validate_min=False, field_classes=None, child_form_kwargs=None):
+    fields=None,
+    exclude=None,
+    extra=1,
+    can_order=False,
+    can_delete=True,
+    max_num=None,
+    formfield_callback=None,
+    widgets=None,
+    validate_max=False,
+    localized_fields=None,
+    labels=None,
+    help_texts=None,
+    error_messages=None,
+    min_num=None,
+    validate_min=False,
+    field_classes=None,
+    child_form_kwargs=None,
+):
     """
     Construct the class for an polymorphic model formset.
 
@@ -285,25 +337,25 @@ def polymorphic_modelformset_factory(model, formset_children,
     :rtype: type
     """
     kwargs = {
-        'model': model,
-        'form': form,
-        'formfield_callback': formfield_callback,
-        'formset': formset,
-        'extra': extra,
-        'can_delete': can_delete,
-        'can_order': can_order,
-        'fields': fields,
-        'exclude': exclude,
-        'min_num': min_num,
-        'max_num': max_num,
-        'widgets': widgets,
-        'validate_min': validate_min,
-        'validate_max': validate_max,
-        'localized_fields': localized_fields,
-        'labels': labels,
-        'help_texts': help_texts,
-        'error_messages': error_messages,
-        'field_classes': field_classes,
+        "model": model,
+        "form": form,
+        "formfield_callback": formfield_callback,
+        "formset": formset,
+        "extra": extra,
+        "can_delete": can_delete,
+        "can_order": can_order,
+        "fields": fields,
+        "exclude": exclude,
+        "min_num": min_num,
+        "max_num": max_num,
+        "widgets": widgets,
+        "validate_min": validate_min,
+        "validate_max": validate_max,
+        "localized_fields": localized_fields,
+        "labels": labels,
+        "help_texts": help_texts,
+        "error_messages": error_messages,
+        "field_classes": field_classes,
     }
     FormSet = modelformset_factory(**kwargs)
 
@@ -313,7 +365,9 @@ def polymorphic_modelformset_factory(model, formset_children,
     if child_form_kwargs:
         child_kwargs.update(child_form_kwargs)
 
-    FormSet.child_forms = polymorphic_child_forms_factory(formset_children, **child_kwargs)
+    FormSet.child_forms = polymorphic_child_forms_factory(
+        formset_children, **child_kwargs
+    )
     return FormSet
 
 
@@ -326,17 +380,34 @@ class BasePolymorphicInlineFormSet(BaseInlineFormSet, BasePolymorphicModelFormSe
         return super(BasePolymorphicInlineFormSet, self)._construct_form(i, **kwargs)
 
 
-def polymorphic_inlineformset_factory(parent_model, model, formset_children,
-                                      formset=BasePolymorphicInlineFormSet, fk_name=None,
+def polymorphic_inlineformset_factory(
+    parent_model,
+    model,
+    formset_children,
+    formset=BasePolymorphicInlineFormSet,
+    fk_name=None,
     # Base field
     # TODO: should these fields be removed in favor of creating
     # the base form as a formset child too?
     form=ModelForm,
-                                      fields=None, exclude=None, extra=1, can_order=False,
-                                      can_delete=True, max_num=None, formfield_callback=None,
-                                      widgets=None, validate_max=False, localized_fields=None,
-                                      labels=None, help_texts=None, error_messages=None,
-                                      min_num=None, validate_min=False, field_classes=None, child_form_kwargs=None):
+    fields=None,
+    exclude=None,
+    extra=1,
+    can_order=False,
+    can_delete=True,
+    max_num=None,
+    formfield_callback=None,
+    widgets=None,
+    validate_max=False,
+    localized_fields=None,
+    labels=None,
+    help_texts=None,
+    error_messages=None,
+    min_num=None,
+    validate_min=False,
+    field_classes=None,
+    child_form_kwargs=None,
+):
     """
     Construct the class for an inline polymorphic formset.
 
@@ -349,27 +420,27 @@ def polymorphic_inlineformset_factory(parent_model, model, formset_children,
     :rtype: type
     """
     kwargs = {
-        'parent_model': parent_model,
-        'model': model,
-        'form': form,
-        'formfield_callback': formfield_callback,
-        'formset': formset,
-        'fk_name': fk_name,
-        'extra': extra,
-        'can_delete': can_delete,
-        'can_order': can_order,
-        'fields': fields,
-        'exclude': exclude,
-        'min_num': min_num,
-        'max_num': max_num,
-        'widgets': widgets,
-        'validate_min': validate_min,
-        'validate_max': validate_max,
-        'localized_fields': localized_fields,
-        'labels': labels,
-        'help_texts': help_texts,
-        'error_messages': error_messages,
-        'field_classes': field_classes,
+        "parent_model": parent_model,
+        "model": model,
+        "form": form,
+        "formfield_callback": formfield_callback,
+        "formset": formset,
+        "fk_name": fk_name,
+        "extra": extra,
+        "can_delete": can_delete,
+        "can_order": can_order,
+        "fields": fields,
+        "exclude": exclude,
+        "min_num": min_num,
+        "max_num": max_num,
+        "widgets": widgets,
+        "validate_min": validate_min,
+        "validate_max": validate_max,
+        "localized_fields": localized_fields,
+        "labels": labels,
+        "help_texts": help_texts,
+        "error_messages": error_messages,
+        "field_classes": field_classes,
     }
     FormSet = inlineformset_factory(**kwargs)
 
@@ -379,5 +450,7 @@ def polymorphic_inlineformset_factory(parent_model, model, formset_children,
     if child_form_kwargs:
         child_kwargs.update(child_form_kwargs)
 
-    FormSet.child_forms = polymorphic_child_forms_factory(formset_children, **child_kwargs)
+    FormSet.child_forms = polymorphic_child_forms_factory(
+        formset_children, **child_kwargs
+    )
     return FormSet

polymorphic/managers.py

@@ -5,14 +5,11 @@ The manager class for use in the models.
 from __future__ import unicode_literals
 
 from django.db import models
+
 from polymorphic.compat import python_2_unicode_compatible
 from polymorphic.query import PolymorphicQuerySet
 
-
-__all__ = (
-    'PolymorphicManager',
-    'PolymorphicQuerySet',
-)
+__all__ = ("PolymorphicManager", "PolymorphicQuerySet")
 
 
 @python_2_unicode_compatible
@@ -23,12 +20,17 @@ class PolymorphicManager(models.Manager):
     Usually not explicitly needed, except if a custom manager or
     a custom queryset class is to be used.
     """
+
     queryset_class = PolymorphicQuerySet
 
     @classmethod
     def from_queryset(cls, queryset_class, class_name=None):
-        manager = super(PolymorphicManager, cls).from_queryset(queryset_class, class_name=class_name)
-        manager.queryset_class = queryset_class  # also set our version, Django uses _queryset_class
+        manager = super(PolymorphicManager, cls).from_queryset(
+            queryset_class, class_name=class_name
+        )
+        manager.queryset_class = (
+            queryset_class
+        )  # also set our version, Django uses _queryset_class
         return manager
 
     def get_queryset(self):
@@ -38,7 +40,10 @@ class PolymorphicManager(models.Manager):
         return qs
 
     def __str__(self):
-        return '%s (PolymorphicManager) using %s' % (self.__class__.__name__, self.queryset_class.__name__)
+        return "%s (PolymorphicManager) using %s" % (
+            self.__class__.__name__,
+            self.queryset_class.__name__,
+        )
 
     # Proxied methods
     def non_polymorphic(self):

polymorphic/models.py

@@ -6,10 +6,14 @@ from __future__ import absolute_import
 
 from django.contrib.contenttypes.models import ContentType
 from django.db import models
-from django.db.models.fields.related import ReverseOneToOneDescriptor, ForwardManyToOneDescriptor
+from django.db.models.fields.related import (
+    ForwardManyToOneDescriptor,
+    ReverseOneToOneDescriptor,
+)
 from django.db.utils import DEFAULT_DB_ALIAS
 
 from polymorphic.compat import with_metaclass
+
 from .base import PolymorphicModelBase
 from .managers import PolymorphicManager
 from .query_translate import translate_polymorphic_Q_object
@@ -44,12 +48,15 @@ class PolymorphicModel(with_metaclass(PolymorphicModelBase, models.Model)):
     # avoid ContentType related field accessor clash (an error emitted by model validation)
     #: The model field that stores the :class:`~django.contrib.contenttypes.models.ContentType` reference to the actual class.
     polymorphic_ctype = models.ForeignKey(
-        ContentType, null=True, editable=False, on_delete=models.CASCADE,
-        related_name='polymorphic_%(app_label)s.%(class)s_set+'
+        ContentType,
+        null=True,
+        editable=False,
+        on_delete=models.CASCADE,
+        related_name="polymorphic_%(app_label)s.%(class)s_set+",
     )
 
     # some applications want to know the name of the fields that are added to its models
-    polymorphic_internal_model_fields = ['polymorphic_ctype']
+    polymorphic_internal_model_fields = ["polymorphic_ctype"]
 
     # Note that Django 1.5 removes these managers because the model is abstract.
     # They are pretended to be there by the metaclass in PolymorphicModelBase.get_inherited_managers()
@@ -73,14 +80,18 @@ class PolymorphicModel(with_metaclass(PolymorphicModelBase, models.Model)):
         # field to figure out the real class of this object
         # (used by PolymorphicQuerySet._get_real_instances)
         if not self.polymorphic_ctype_id:
-            self.polymorphic_ctype = ContentType.objects.db_manager(using).get_for_model(self, for_concrete_model=False)
+            self.polymorphic_ctype = ContentType.objects.db_manager(
+                using
+            ).get_for_model(self, for_concrete_model=False)
+
     pre_save_polymorphic.alters_data = True
 
     def save(self, *args, **kwargs):
         """Calls :meth:`pre_save_polymorphic` and saves the model."""
-        using = kwargs.get('using', self._state.db or DEFAULT_DB_ALIAS)
+        using = kwargs.get("using", self._state.db or DEFAULT_DB_ALIAS)
         self.pre_save_polymorphic(using=using)
         return super(PolymorphicModel, self).save(*args, **kwargs)
+
     save.alters_data = True
 
     def get_real_instance_class(self):
@@ -92,28 +103,40 @@ class PolymorphicModel(with_metaclass(PolymorphicModelBase, models.Model)):
         determined using this method.
         """
         if self.polymorphic_ctype_id is None:
-            raise PolymorphicTypeUndefined((
+            raise PolymorphicTypeUndefined(
+                (
                     "The model {}#{} does not have a `polymorphic_ctype_id` value defined.\n"
                     "If you created models outside polymorphic, e.g. through an import or migration, "
                     "make sure the `polymorphic_ctype_id` field points to the ContentType ID of the model subclass."
-            ).format(self.__class__.__name__, self.pk))
+                ).format(self.__class__.__name__, self.pk)
+            )
 
         # the following line would be the easiest way to do this, but it produces sql queries
         # return self.polymorphic_ctype.model_class()
         # so we use the following version, which uses the ContentType manager cache.
         # Note that model_class() can return None for stale content types;
         # when the content type record still exists but no longer refers to an existing model.
-        model = ContentType.objects.db_manager(self._state.db).get_for_id(self.polymorphic_ctype_id).model_class()
+        model = (
+            ContentType.objects.db_manager(self._state.db)
+            .get_for_id(self.polymorphic_ctype_id)
+            .model_class()
+        )
 
         # Protect against bad imports (dumpdata without --natural) or other
         # issues missing with the ContentType models.
-        if model is not None \
-                and not issubclass(model, self.__class__) \
-                and (self.__class__._meta.proxy_for_model is None \
-                     or not issubclass(model, self.__class__._meta.proxy_for_model)):
-            raise PolymorphicTypeInvalid("ContentType {0} for {1} #{2} does not point to a subclass!".format(
-                self.polymorphic_ctype_id, model, self.pk,
-            ))
+        if (
+            model is not None
+            and not issubclass(model, self.__class__)
+            and (
+                self.__class__._meta.proxy_for_model is None
+                or not issubclass(model, self.__class__._meta.proxy_for_model)
+            )
+        ):
+            raise PolymorphicTypeInvalid(
+                "ContentType {0} for {1} #{2} does not point to a subclass!".format(
+                    self.polymorphic_ctype_id, model, self.pk
+                )
+            )
 
         return model
 
@@ -121,13 +144,21 @@ class PolymorphicModel(with_metaclass(PolymorphicModelBase, models.Model)):
         model_class = self.get_real_instance_class()
         if model_class is None:
             return None
-        return ContentType.objects.db_manager(self._state.db).get_for_model(model_class, for_concrete_model=True).pk
+        return (
+            ContentType.objects.db_manager(self._state.db)
+            .get_for_model(model_class, for_concrete_model=True)
+            .pk
+        )
 
     def get_real_concrete_instance_class(self):
         model_class = self.get_real_instance_class()
         if model_class is None:
             return None
-        return ContentType.objects.db_manager(self._state.db).get_for_model(model_class, for_concrete_model=True).model_class()
+        return (
+            ContentType.objects.db_manager(self._state.db)
+            .get_for_model(model_class, for_concrete_model=True)
+            .model_class()
+        )
 
     def get_real_instance(self):
         """
@@ -176,15 +207,25 @@ class PolymorphicModel(with_metaclass(PolymorphicModelBase, models.Model)):
             def accessor_function(self):
                 attr = model._base_objects.get(pk=self.pk)
                 return attr
+
             return accessor_function
 
-        subclasses_and_superclasses_accessors = self._get_inheritance_relation_fields_and_models()
+        subclasses_and_superclasses_accessors = (
+            self._get_inheritance_relation_fields_and_models()
+        )
 
         for name, model in subclasses_and_superclasses_accessors.items():
             # Here be dragons.
             orig_accessor = getattr(self.__class__, name, None)
-            if issubclass(type(orig_accessor), (ReverseOneToOneDescriptor, ForwardManyToOneDescriptor)):
-                setattr(self.__class__, name, property(create_accessor_function_for_model(model, name)))
+            if issubclass(
+                type(orig_accessor),
+                (ReverseOneToOneDescriptor, ForwardManyToOneDescriptor),
+            ):
+                setattr(
+                    self.__class__,
+                    name,
+                    property(create_accessor_function_for_model(model, name)),
+                )
 
     def _get_inheritance_relation_fields_and_models(self):
         """helper function for __init__:
@@ -194,31 +235,45 @@ class PolymorphicModel(with_metaclass(PolymorphicModelBase, models.Model)):
             result[field_name] = model
 
         def add_model_if_regular(model, field_name, result):
-            if (issubclass(model, models.Model)
+            if (
+                issubclass(model, models.Model)
                 and model != models.Model
                 and model != self.__class__
-                    and model != PolymorphicModel):
+                and model != PolymorphicModel
+            ):
                 add_model(model, field_name, result)
 
         def add_all_super_models(model, result):
             for super_cls, field_to_super in model._meta.parents.items():
                 if field_to_super is not None:  # if not a link to a proxy model
-                    field_name = field_to_super.name  # the field on model can have a different name to super_cls._meta.module_name, if the field is created manually using 'parent_link'
+                    field_name = (
+                        field_to_super.name
+                    )  # the field on model can have a different name to super_cls._meta.module_name, if the field is created manually using 'parent_link'
                     add_model_if_regular(super_cls, field_name, result)
                     add_all_super_models(super_cls, result)
 
         def add_all_sub_models(super_cls, result):
-            for sub_cls in super_cls.__subclasses__():  # go through all subclasses of model
-                if super_cls in sub_cls._meta.parents:  # super_cls may not be in sub_cls._meta.parents if super_cls is a proxy model
-                    field_to_super = sub_cls._meta.parents[super_cls]  # get the field that links sub_cls to super_cls
-                    if field_to_super is not None:    # if filed_to_super is not a link to a proxy model
+            for (
+                sub_cls
+            ) in super_cls.__subclasses__():  # go through all subclasses of model
+                if (
+                    super_cls in sub_cls._meta.parents
+                ):  # super_cls may not be in sub_cls._meta.parents if super_cls is a proxy model
+                    field_to_super = sub_cls._meta.parents[
+                        super_cls
+                    ]  # get the field that links sub_cls to super_cls
+                    if (
+                        field_to_super is not None
+                    ):  # if filed_to_super is not a link to a proxy model
                         super_to_sub_related_field = field_to_super.remote_field
                         if super_to_sub_related_field.related_name is None:
                             # if related name is None the related field is the name of the subclass
                             to_subclass_fieldname = sub_cls.__name__.lower()
                         else:
                             # otherwise use the given related name
-                            to_subclass_fieldname = super_to_sub_related_field.related_name
+                            to_subclass_fieldname = (
+                                super_to_sub_related_field.related_name
+                            )
 
                         add_model_if_regular(sub_cls, to_subclass_fieldname, result)
 

polymorphic/query.py

@@ -12,8 +12,12 @@ from django.db.models import FieldDoesNotExist
 from django.db.models.query import ModelIterable, Q, QuerySet
 
 from . import compat
-from .query_translate import translate_polymorphic_filter_definitions_in_kwargs, translate_polymorphic_filter_definitions_in_args
-from .query_translate import translate_polymorphic_field_path, translate_polymorphic_Q_object
+from .query_translate import (
+    translate_polymorphic_field_path,
+    translate_polymorphic_filter_definitions_in_args,
+    translate_polymorphic_filter_definitions_in_kwargs,
+    translate_polymorphic_Q_object,
+)
 
 # chunk-size: maximum number of objects requested per db-request
 # by the polymorphic queryset.iterator() implementation
@@ -72,7 +76,7 @@ def transmogrify(cls, obj):
     """
     Upcast a class to a different type without asking questions.
     """
-    if '__init__' not in obj.__dict__:
+    if "__init__" not in obj.__dict__:
         # Just assign __class__ to a different value.
         new = obj
         new.__class__ = cls
@@ -87,6 +91,7 @@ def transmogrify(cls, obj):
 ###################################################################################
 # PolymorphicQuerySet
 
+
 class PolymorphicQuerySet(QuerySet):
     """
     QuerySet for PolymorphicModel
@@ -115,14 +120,17 @@ class PolymorphicQuerySet(QuerySet):
         new.polymorphic_disabled = self.polymorphic_disabled
         new.polymorphic_deferred_loading = (
             copy.copy(self.polymorphic_deferred_loading[0]),
-            self.polymorphic_deferred_loading[1])
+            self.polymorphic_deferred_loading[1],
+        )
         return new
 
     def as_manager(cls):
         from .managers import PolymorphicManager
+
         manager = PolymorphicManager.from_queryset(cls)()
         manager._built_with_as_manager = True
         return manager
+
     as_manager.queryset_only = True
     as_manager = classmethod(as_manager)
 
@@ -154,15 +162,22 @@ class PolymorphicQuerySet(QuerySet):
 
     def _filter_or_exclude(self, negate, *args, **kwargs):
         # We override this internal Django functon as it is used for all filter member functions.
-        q_objects = translate_polymorphic_filter_definitions_in_args(self.model, args, using=self.db)  # the Q objects
-        additional_args = translate_polymorphic_filter_definitions_in_kwargs(self.model, kwargs, using=self.db)  # filter_field='data'
-        return super(PolymorphicQuerySet, self)._filter_or_exclude(negate, *(list(q_objects) + additional_args), **kwargs)
+        q_objects = translate_polymorphic_filter_definitions_in_args(
+            self.model, args, using=self.db
+        )  # the Q objects
+        additional_args = translate_polymorphic_filter_definitions_in_kwargs(
+            self.model, kwargs, using=self.db
+        )  # filter_field='data'
+        return super(PolymorphicQuerySet, self)._filter_or_exclude(
+            negate, *(list(q_objects) + additional_args), **kwargs
+        )
 
     def order_by(self, *field_names):
         """translate the field paths in the args, then call vanilla order_by."""
         field_names = [
             translate_polymorphic_field_path(self.model, a)
-            if isinstance(a, compat.string_types) else a  # allow expressions to pass unchanged
+            if isinstance(a, compat.string_types)
+            else a  # allow expressions to pass unchanged
             for a in field_names
         ]
         return super(PolymorphicQuerySet, self).order_by(*field_names)
@@ -213,8 +228,8 @@ class PolymorphicQuerySet(QuerySet):
         """
         existing, defer = self.polymorphic_deferred_loading
         field_names = set(field_names)
-        if 'pk' in field_names:
-            field_names.remove('pk')
+        if "pk" in field_names:
+            field_names.remove("pk")
             field_names.add(self.model._meta.pk.name)
 
         if defer:
@@ -228,14 +243,14 @@ class PolymorphicQuerySet(QuerySet):
     def _process_aggregate_args(self, args, kwargs):
         """for aggregate and annotate kwargs: allow ModelX___field syntax for kwargs, forbid it for args.
         Modifies kwargs if needed (these are Aggregate objects, we translate the lookup member variable)"""
-        ___lookup_assert_msg = 'PolymorphicModel: annotate()/aggregate(): ___ model lookup supported for keyword arguments only'
+        ___lookup_assert_msg = "PolymorphicModel: annotate()/aggregate(): ___ model lookup supported for keyword arguments only"
 
         def patch_lookup(a):
             # The field on which the aggregate operates is
             # stored inside a complex query expression.
             if isinstance(a, Q):
                 translate_polymorphic_Q_object(self.model, a)
-            elif hasattr(a, 'get_source_expressions'):
+            elif hasattr(a, "get_source_expressions"):
                 for source_expression in a.get_source_expressions():
                     if source_expression is not None:
                         patch_lookup(source_expression)
@@ -246,6 +261,7 @@ class PolymorphicQuerySet(QuerySet):
             """ *args might be complex expressions too in django 1.8 so
             the testing for a '___' is rather complex on this one """
             if isinstance(a, Q):
+
                 def tree_node_test___lookup(my_model, node):
                     " process all children of this Q node "
                     for i in range(len(node.children)):
@@ -253,17 +269,17 @@ class PolymorphicQuerySet(QuerySet):
 
                         if type(child) == tuple:
                             # this Q object child is a tuple => a kwarg like Q( instance_of=ModelB )
-                            assert '___' not in child[0], ___lookup_assert_msg
+                            assert "___" not in child[0], ___lookup_assert_msg
                         else:
                             # this Q object child is another Q object, recursively process this as well
                             tree_node_test___lookup(my_model, child)
 
                 tree_node_test___lookup(self.model, a)
-            elif hasattr(a, 'get_source_expressions'):
+            elif hasattr(a, "get_source_expressions"):
                 for source_expression in a.get_source_expressions():
                     test___lookup(source_expression)
             else:
-                assert '___' not in a.name, ___lookup_assert_msg
+                assert "___" not in a.name, ___lookup_assert_msg
 
         for a in args:
             test___lookup(a)
@@ -344,8 +360,12 @@ class PolymorphicQuerySet(QuerySet):
         # - sort base_result_object ids into idlist_per_model lists, depending on their real class;
         # - store objects that already have the correct class into "results"
         content_type_manager = ContentType.objects.db_manager(self.db)
-        self_model_class_id = content_type_manager.get_for_model(self.model, for_concrete_model=False).pk
-        self_concrete_model_class_id = content_type_manager.get_for_model(self.model, for_concrete_model=True).pk
+        self_model_class_id = content_type_manager.get_for_model(
+            self.model, for_concrete_model=False
+        ).pk
+        self_concrete_model_class_id = content_type_manager.get_for_model(
+            self.model, for_concrete_model=True
+        ).pk
 
         for i, base_object in enumerate(base_result_objects):
 
@@ -354,7 +374,9 @@ class PolymorphicQuerySet(QuerySet):
                 resultlist.append(base_object)
             else:
                 real_concrete_class = base_object.get_real_instance_class()
-                real_concrete_class_id = base_object.get_real_concrete_instance_class_id()
+                real_concrete_class_id = (
+                    base_object.get_real_concrete_instance_class_id()
+                )
 
                 if real_concrete_class_id is None:
                     # Dealing with a stale content type
@@ -365,9 +387,15 @@ class PolymorphicQuerySet(QuerySet):
                     resultlist.append(transmogrify(real_concrete_class, base_object))
                 else:
                     # This model has a concrete derived class, track it for bulk retrieval.
-                    real_concrete_class = content_type_manager.get_for_id(real_concrete_class_id).model_class()
-                    idlist_per_model[real_concrete_class].append(getattr(base_object, pk_name))
-                    indexlist_per_model[real_concrete_class].append((i, len(resultlist)))
+                    real_concrete_class = content_type_manager.get_for_id(
+                        real_concrete_class_id
+                    ).model_class()
+                    idlist_per_model[real_concrete_class].append(
+                        getattr(base_object, pk_name)
+                    )
+                    indexlist_per_model[real_concrete_class].append(
+                        (i, len(resultlist))
+                    )
                     resultlist.append(None)
 
         # For each model in "idlist_per_model" request its objects (the real model)
@@ -377,10 +405,12 @@ class PolymorphicQuerySet(QuerySet):
         # TODO: defer(), only(): support for these would be around here
         for real_concrete_class, idlist in idlist_per_model.items():
             indices = indexlist_per_model[real_concrete_class]
-            real_objects = real_concrete_class._base_objects.db_manager(self.db).filter(**{
-                ('%s__in' % pk_name): idlist,
-            })
-            real_objects.query.select_related = self.query.select_related  # copy select related configuration to new qs
+            real_objects = real_concrete_class._base_objects.db_manager(self.db).filter(
+                **{("%s__in" % pk_name): idlist}
+            )
+            real_objects.query.select_related = (
+                self.query.select_related
+            )  # copy select related configuration to new qs
 
             # Copy deferred fields configuration to the new queryset
             deferred_loading_fields = []
@@ -388,14 +418,15 @@ class PolymorphicQuerySet(QuerySet):
             for field in existing_fields:
                 try:
                     translated_field_name = translate_polymorphic_field_path(
-                        real_concrete_class, field)
+                        real_concrete_class, field
+                    )
                 except AssertionError:
-                    if '___' in field:
+                    if "___" in field:
                         # The originally passed argument to .defer() or .only()
                         # was in the form Model2B___field2, where Model2B is
                         # now a superclass of real_concrete_class. Thus it's
                         # sufficient to just use the field name.
-                        translated_field_name = field.rpartition('___')[-1]
+                        translated_field_name = field.rpartition("___")[-1]
 
                         # Check if the field does exist.
                         # Ignore deferred fields that don't exist in this subclass type.
@@ -407,7 +438,10 @@ class PolymorphicQuerySet(QuerySet):
                         raise
 
                 deferred_loading_fields.append(translated_field_name)
-            real_objects.query.deferred_loading = (set(deferred_loading_fields), self.query.deferred_loading[1])
+            real_objects.query.deferred_loading = (
+                set(deferred_loading_fields),
+                self.query.deferred_loading[1],
+            )
 
             real_objects_dict = {
                 getattr(real_object, pk_name): real_object
@@ -445,13 +479,17 @@ class PolymorphicQuerySet(QuerySet):
 
         # set polymorphic_annotate_names in all objects (currently just used for debugging/printing)
         if self.query.annotations:
-            annotate_names = list(self.query.annotations.keys())  # get annotate field list
+            annotate_names = list(
+                self.query.annotations.keys()
+            )  # get annotate field list
             for real_object in resultlist:
                 real_object.polymorphic_annotate_names = annotate_names
 
         # set polymorphic_extra_select_names in all objects (currently just used for debugging/printing)
         if self.query.extra_select:
-            extra_select_names = list(self.query.extra_select.keys())  # get extra select field list
+            extra_select_names = list(
+                self.query.extra_select.keys()
+            )  # get extra select field list
             for real_object in resultlist:
                 real_object.polymorphic_extra_select_names = extra_select_names
 
@@ -460,15 +498,14 @@ class PolymorphicQuerySet(QuerySet):
     def __repr__(self, *args, **kwargs):
         if self.model.polymorphic_query_multiline_output:
             result = [repr(o) for o in self.all()]
-            return '[ ' + ',\n  '.join(result) + ' ]'
+            return "[ " + ",\n  ".join(result) + " ]"
         else:
             return super(PolymorphicQuerySet, self).__repr__(*args, **kwargs)
 
     class _p_list_class(list):
-
         def __repr__(self, *args, **kwargs):
             result = [repr(o) for o in self]
-            return '[ ' + ',\n  '.join(result) + ' ]'
+            return "[ " + ",\n  ".join(result) + " ]"
 
     def get_real_instances(self, base_result_objects=None):
         """

polymorphic/query_translate.py

@@ -15,18 +15,19 @@ from django.db.models import Q
 from django.db.models.fields.related import ForeignObjectRel, RelatedField
 from django.db.utils import DEFAULT_DB_ALIAS
 
-
-###################################################################################
-# PolymorphicQuerySet support functions
-
 # These functions implement the additional filter- and Q-object functionality.
 # They form a kind of small framework for easily adding more
 # functionality to filters and Q objects.
 # Probably a more general queryset enhancement class could be made out of them.
 from polymorphic import compat
 
+###################################################################################
+# PolymorphicQuerySet support functions
 
-def translate_polymorphic_filter_definitions_in_kwargs(queryset_model, kwargs, using=DEFAULT_DB_ALIAS):
+
+def translate_polymorphic_filter_definitions_in_kwargs(
+    queryset_model, kwargs, using=DEFAULT_DB_ALIAS
+):
     """
     Translate the keyword argument list for PolymorphicQuerySet.filter()
 
@@ -43,21 +44,25 @@ def translate_polymorphic_filter_definitions_in_kwargs(queryset_model, kwargs, u
     additional_args = []
     for field_path, val in kwargs.copy().items():  # Python 3 needs copy
 
-        new_expr = _translate_polymorphic_filter_definition(queryset_model, field_path, val, using=using)
+        new_expr = _translate_polymorphic_filter_definition(
+            queryset_model, field_path, val, using=using
+        )
 
         if type(new_expr) == tuple:
             # replace kwargs element
-            del(kwargs[field_path])
+            del kwargs[field_path]
             kwargs[new_expr[0]] = new_expr[1]
 
         elif isinstance(new_expr, models.Q):
-            del(kwargs[field_path])
+            del kwargs[field_path]
             additional_args.append(new_expr)
 
     return additional_args
 
 
-def translate_polymorphic_Q_object(queryset_model, potential_q_object, using=DEFAULT_DB_ALIAS):
+def translate_polymorphic_Q_object(
+    queryset_model, potential_q_object, using=DEFAULT_DB_ALIAS
+):
     def tree_node_correct_field_specs(my_model, node):
         " process all children of this Q node "
         for i in range(len(node.children)):
@@ -66,7 +71,9 @@ def translate_polymorphic_Q_object(queryset_model, potential_q_object, using=DEF
             if type(child) == tuple:
                 # this Q object child is a tuple => a kwarg like Q( instance_of=ModelB )
                 key, val = child
-                new_expr = _translate_polymorphic_filter_definition(my_model, key, val, using=using)
+                new_expr = _translate_polymorphic_filter_definition(
+                    my_model, key, val, using=using
+                )
                 if new_expr:
                     node.children[i] = new_expr
             else:
@@ -79,7 +86,9 @@ def translate_polymorphic_Q_object(queryset_model, potential_q_object, using=DEF
     return potential_q_object
 
 
-def translate_polymorphic_filter_definitions_in_args(queryset_model, args, using=DEFAULT_DB_ALIAS):
+def translate_polymorphic_filter_definitions_in_args(
+    queryset_model, args, using=DEFAULT_DB_ALIAS
+):
     """
     Translate the non-keyword argument list for PolymorphicQuerySet.filter()
 
@@ -90,10 +99,15 @@ def translate_polymorphic_filter_definitions_in_args(queryset_model, args, using
 
     Returns: modified Q objects
     """
-    return [translate_polymorphic_Q_object(queryset_model, copy.deepcopy(q), using=using) for q in args]
+    return [
+        translate_polymorphic_Q_object(queryset_model, copy.deepcopy(q), using=using)
+        for q in args
+    ]
 
 
-def _translate_polymorphic_filter_definition(queryset_model, field_path, field_val, using=DEFAULT_DB_ALIAS):
+def _translate_polymorphic_filter_definition(
+    queryset_model, field_path, field_val, using=DEFAULT_DB_ALIAS
+):
     """
     Translate a keyword argument (field_path=field_val), as used for
     PolymorphicQuerySet.filter()-like functions (and Q objects).
@@ -107,11 +121,11 @@ def _translate_polymorphic_filter_definition(queryset_model, field_path, field_v
 
     # handle instance_of expressions or alternatively,
     # if this is a normal Django filter expression, return None
-    if field_path == 'instance_of':
+    if field_path == "instance_of":
         return create_instanceof_q(field_val, using=using)
-    elif field_path == 'not_instance_of':
+    elif field_path == "not_instance_of":
         return create_instanceof_q(field_val, not_instance_of=True, using=using)
-    elif '___' not in field_path:
+    elif "___" not in field_path:
         return None  # no change
 
     # filter expression contains '___' (i.e. filter for polymorphic field)
@@ -133,23 +147,32 @@ def translate_polymorphic_field_path(queryset_model, field_path):
     if not isinstance(field_path, compat.string_types):
         raise ValueError("Expected field name as string: {0}".format(field_path))
 
-    classname, sep, pure_field_path = field_path.partition('___')
+    classname, sep, pure_field_path = field_path.partition("___")
     if not sep:
         return field_path
-    assert classname, 'PolymorphicModel: %s: bad field specification' % field_path
+    assert classname, "PolymorphicModel: %s: bad field specification" % field_path
 
     negated = False
-    if classname[0] == '-':
+    if classname[0] == "-":
         negated = True
-        classname = classname.lstrip('-')
+        classname = classname.lstrip("-")
 
-    if '__' in classname:
+    if "__" in classname:
         # the user has app label prepended to class name via __ => use Django's get_model function
-        appname, sep, classname = classname.partition('__')
+        appname, sep, classname = classname.partition("__")
         model = apps.get_model(appname, classname)
-        assert model, 'PolymorphicModel: model %s (in app %s) not found!' % (model.__name__, appname)
+        assert model, "PolymorphicModel: model %s (in app %s) not found!" % (
+            model.__name__,
+            appname,
+        )
         if not issubclass(model, queryset_model):
-            e = 'PolymorphicModel: queryset filter error: "' + model.__name__ + '" is not derived from "' + queryset_model.__name__ + '"'
+            e = (
+                'PolymorphicModel: queryset filter error: "'
+                + model.__name__
+                + '" is not derived from "'
+                + queryset_model.__name__
+                + '"'
+            )
             raise AssertionError(e)
 
     else:
@@ -171,18 +194,21 @@ def translate_polymorphic_field_path(queryset_model, field_path):
 
         submodels = _get_all_sub_models(queryset_model)
         model = submodels.get(classname, None)
-        assert model, 'PolymorphicModel: model %s not found (not a subclass of %s)!' % (classname, queryset_model.__name__)
+        assert model, "PolymorphicModel: model %s not found (not a subclass of %s)!" % (
+            classname,
+            queryset_model.__name__,
+        )
 
     basepath = _create_base_path(queryset_model, model)
 
     if negated:
-        newpath = '-'
+        newpath = "-"
     else:
-        newpath = ''
+        newpath = ""
 
     newpath += basepath
     if basepath:
-        newpath += '__'
+        newpath += "__"
 
     newpath += pure_field_path
     return newpath
@@ -199,11 +225,13 @@ def _get_all_sub_models(base_model):
             # model name is occurring twice in submodel inheritance tree => Error
             if model.__name__ in result and model != result[model.__name__]:
                 raise FieldError(
-                    'PolymorphicModel: model name alone is ambiguous: %s.%s and %s.%s match!\n'
-                    'In this case, please use the syntax: applabel__ModelName___field' % (
-                        model._meta.app_label, model.__name__,
+                    "PolymorphicModel: model name alone is ambiguous: %s.%s and %s.%s match!\n"
+                    "In this case, please use the syntax: applabel__ModelName___field"
+                    % (
+                        model._meta.app_label,
+                        model.__name__,
                         result[model.__name__]._meta.app_label,
-                        result[model.__name__].__name__
+                        result[model.__name__].__name__,
                     )
                 )
 
@@ -225,8 +253,8 @@ def _create_base_path(baseclass, myclass):
             if b._meta.abstract or b._meta.proxy:
                 return _get_query_related_name(myclass)
             else:
-                return path + '__' + _get_query_related_name(myclass)
-    return ''
+                return path + "__" + _get_query_related_name(myclass)
+    return ""
 
 
 def _get_query_related_name(myclass):
@@ -256,12 +284,13 @@ def create_instanceof_q(modellist, not_instance_of=False, using=DEFAULT_DB_ALIAS
 
     if not isinstance(modellist, (list, tuple)):
         from .models import PolymorphicModel
+
         if issubclass(modellist, PolymorphicModel):
             modellist = [modellist]
         else:
             raise TypeError(
-                'PolymorphicModel: instance_of expects a list of (polymorphic) '
-                'models or a single (polymorphic) model'
+                "PolymorphicModel: instance_of expects a list of (polymorphic) "
+                "models or a single (polymorphic) model"
             )
 
     contenttype_ids = _get_mro_content_type_ids(modellist, using)
@@ -274,7 +303,9 @@ def create_instanceof_q(modellist, not_instance_of=False, using=DEFAULT_DB_ALIAS
 def _get_mro_content_type_ids(models, using):
     contenttype_ids = set()
     for model in models:
-        ct = ContentType.objects.db_manager(using).get_for_model(model, for_concrete_model=False)
+        ct = ContentType.objects.db_manager(using).get_for_model(
+            model, for_concrete_model=False
+        )
         contenttype_ids.add(ct.pk)
         subclasses = model.__subclasses__()
         if subclasses:

polymorphic/showfields.py

@@ -6,15 +6,16 @@ from django.db import models
 from . import compat
 from .compat import python_2_unicode_compatible
 
-
-RE_DEFERRED = re.compile('_Deferred_.*')
+RE_DEFERRED = re.compile("_Deferred_.*")
 
 
 @python_2_unicode_compatible
 class ShowFieldBase(object):
     """ base class for the ShowField... model mixins, does the work """
 
-    polymorphic_query_multiline_output = True  # cause nicer multiline PolymorphicQuery output
+    polymorphic_query_multiline_output = (
+        True
+    )  # cause nicer multiline PolymorphicQuery output
 
     polymorphic_showfield_type = False
     polymorphic_showfield_content = False
@@ -32,24 +33,24 @@ class ShowFieldBase(object):
         "helper for __unicode__"
         content = getattr(self, field_name)
         if self.polymorphic_showfield_old_format:
-            out = ': '
+            out = ": "
         else:
-            out = ' '
+            out = " "
         if issubclass(field_type, models.ForeignKey):
             if content is None:
-                out += 'None'
+                out += "None"
             else:
                 out += content.__class__.__name__
         elif issubclass(field_type, models.ManyToManyField):
-            out += '%d' % content.count()
+            out += "%d" % content.count()
         elif isinstance(content, compat.integer_types):
             out += str(content)
         elif content is None:
-            out += 'None'
+            out += "None"
         else:
             txt = str(content)
             if len(txt) > self.polymorphic_showfield_max_field_width:
-                txt = txt[:self.polymorphic_showfield_max_field_width - 2] + '..'
+                txt = txt[: self.polymorphic_showfield_max_field_width - 2] + ".."
             out += '"' + txt + '"'
         return out
 
@@ -57,7 +58,10 @@ class ShowFieldBase(object):
         "helper for __unicode__"
         done_fields = set()
         for field in self._meta.fields + self._meta.many_to_many:
-            if field.name in self.polymorphic_internal_model_fields or '_ptr' in field.name:
+            if (
+                field.name in self.polymorphic_internal_model_fields
+                or "_ptr" in field.name
+            ):
                 continue
             if field.name in done_fields:
                 continue  # work around django diamond inheritance problem
@@ -66,78 +70,90 @@ class ShowFieldBase(object):
             out = field.name
 
             # if this is the standard primary key named "id", print it as we did with older versions of django_polymorphic
-            if field.primary_key and field.name == 'id' and type(field) == models.AutoField:
-                out += ' ' + str(getattr(self, field.name))
+            if (
+                field.primary_key
+                and field.name == "id"
+                and type(field) == models.AutoField
+            ):
+                out += " " + str(getattr(self, field.name))
 
             # otherwise, display it just like all other fields (with correct type, shortened content etc.)
             else:
                 if self.polymorphic_showfield_type:
-                    out += ' (' + type(field).__name__
+                    out += " (" + type(field).__name__
                     if field.primary_key:
-                        out += '/pk'
-                    out += ')'
+                        out += "/pk"
+                    out += ")"
 
                 if self.polymorphic_showfield_content:
                     out += self._showfields_get_content(field.name, type(field))
 
-            parts.append((False, out, ','))
+            parts.append((False, out, ","))
 
     def _showfields_add_dynamic_fields(self, field_list, title, parts):
         "helper for __unicode__"
-        parts.append((True, '- ' + title, ':'))
+        parts.append((True, "- " + title, ":"))
         for field_name in field_list:
             out = field_name
             content = getattr(self, field_name)
             if self.polymorphic_showfield_type:
-                out += ' (' + type(content).__name__ + ')'
+                out += " (" + type(content).__name__ + ")"
             if self.polymorphic_showfield_content:
                 out += self._showfields_get_content(field_name)
 
-            parts.append((False, out, ','))
+            parts.append((False, out, ","))
 
     def __str__(self):
         # create list ("parts") containing one tuple for each title/field:
         # ( bool: new section , item-text , separator to use after item )
 
         # start with model name
-        parts = [(True, RE_DEFERRED.sub('', self.__class__.__name__), ':')]
+        parts = [(True, RE_DEFERRED.sub("", self.__class__.__name__), ":")]
 
         # add all regular fields
         self._showfields_add_regular_fields(parts)
 
         # add annotate fields
-        if hasattr(self, 'polymorphic_annotate_names'):
-            self._showfields_add_dynamic_fields(self.polymorphic_annotate_names, 'Ann', parts)
+        if hasattr(self, "polymorphic_annotate_names"):
+            self._showfields_add_dynamic_fields(
+                self.polymorphic_annotate_names, "Ann", parts
+            )
 
         # add extra() select fields
-        if hasattr(self, 'polymorphic_extra_select_names'):
-            self._showfields_add_dynamic_fields(self.polymorphic_extra_select_names, 'Extra', parts)
+        if hasattr(self, "polymorphic_extra_select_names"):
+            self._showfields_add_dynamic_fields(
+                self.polymorphic_extra_select_names, "Extra", parts
+            )
 
         if self.polymorphic_showfield_deferred:
             fields = self.get_deferred_fields()
             if fields:
-                parts.append((False, "deferred[{0}]".format(",".join(sorted(fields))), ''))
+                parts.append(
+                    (False, "deferred[{0}]".format(",".join(sorted(fields))), "")
+                )
 
         # format result
 
         indent = len(self.__class__.__name__) + 5
-        indentstr = ''.rjust(indent)
-        out = ''
+        indentstr = "".rjust(indent)
+        out = ""
         xpos = 0
         possible_line_break_pos = None
 
         for i in range(len(parts)):
             new_section, p, separator = parts[i]
-            final = (i == len(parts) - 1)
+            final = i == len(parts) - 1
             if not final:
                 next_new_section, _, _ = parts[i + 1]
 
-            if (self.polymorphic_showfield_max_line_width
+            if (
+                self.polymorphic_showfield_max_line_width
                 and xpos + len(p) > self.polymorphic_showfield_max_line_width
-                    and possible_line_break_pos is not None):
+                and possible_line_break_pos is not None
+            ):
                 rest = out[possible_line_break_pos:]
                 out = out[:possible_line_break_pos]
-                out += '\n' + indentstr + rest
+                out += "\n" + indentstr + rest
                 xpos = indent + len(rest)
 
             out += p
@@ -147,26 +163,29 @@ class ShowFieldBase(object):
                 if not next_new_section:
                     out += separator
                     xpos += len(separator)
-                out += ' '
+                out += " "
                 xpos += 1
 
             if not new_section:
                 possible_line_break_pos = len(out)
 
-        return '<' + out + '>'
+        return "<" + out + ">"
 
 
 class ShowFieldType(ShowFieldBase):
     """ model mixin that shows the object's class and it's field types """
+
     polymorphic_showfield_type = True
 
 
 class ShowFieldContent(ShowFieldBase):
     """ model mixin that shows the object's class, it's fields and field contents """
+
     polymorphic_showfield_content = True
 
 
 class ShowFieldTypeAndContent(ShowFieldBase):
     """ model mixin, like ShowFieldContent, but also show field types """
+
     polymorphic_showfield_type = True
     polymorphic_showfield_content = True

polymorphic/templatetags/polymorphic_admin_tags.py

@@ -1,11 +1,11 @@
 from django.template import Library, Node, TemplateSyntaxError
+
 from polymorphic import compat
 
 register = Library()
 
 
 class BreadcrumbScope(Node):
-
     def __init__(self, base_opts, nodelist):
         self.base_opts = base_opts
         self.nodelist = nodelist  # Note, takes advantage of Node.child_nodelists
@@ -16,15 +16,14 @@ class BreadcrumbScope(Node):
         if len(bits) == 2:
             (tagname, base_opts) = bits
             base_opts = parser.compile_filter(base_opts)
-            nodelist = parser.parse(('endbreadcrumb_scope',))
+            nodelist = parser.parse(("endbreadcrumb_scope",))
             parser.delete_first_token()
 
-            return cls(
-                base_opts=base_opts,
-                nodelist=nodelist
-            )
+            return cls(base_opts=base_opts, nodelist=nodelist)
         else:
-            raise TemplateSyntaxError("{0} tag expects 1 argument".format(token.contents[0]))
+            raise TemplateSyntaxError(
+                "{0} tag expects 1 argument".format(token.contents[0])
+            )
 
     def render(self, context):
         # app_label is really hard to overwrite in the standard Django ModelAdmin.
@@ -34,8 +33,8 @@ class BreadcrumbScope(Node):
         new_vars = {}
         if base_opts and not isinstance(base_opts, compat.string_types):
             new_vars = {
-                'app_label': base_opts.app_label,  # What this is all about
-                'opts': base_opts,
+                "app_label": base_opts.app_label,  # What this is all about
+                "opts": base_opts,
             }
 
         new_scope = context.push()

polymorphic/templatetags/polymorphic_formset_tags.py

@@ -7,7 +7,6 @@ from django.utils.translation import ugettext
 
 from polymorphic.formsets import BasePolymorphicModelFormSet
 
-
 register = Library()
 
 
@@ -19,7 +18,7 @@ def include_empty_form(formset):
     for form in formset:
         yield form
 
-    if hasattr(formset, 'empty_forms'):
+    if hasattr(formset, "empty_forms"):
         # BasePolymorphicModelFormSet
         for form in formset.empty_forms:
             yield form
@@ -40,24 +39,25 @@ def as_script_options(formset):
     - ``add_text``
     - ``show_add_button``
     """
-    verbose_name = getattr(formset, 'verbose_name', formset.model._meta.verbose_name)
+    verbose_name = getattr(formset, "verbose_name", formset.model._meta.verbose_name)
     options = {
-        'prefix': formset.prefix,
-        'pkFieldName': formset.model._meta.pk.name,
-        'addText': getattr(formset, 'add_text', None) or ugettext('Add another %(verbose_name)s') % {
-            'verbose_name': capfirst(verbose_name),
-        },
-        'showAddButton': getattr(formset, 'show_add_button', True),
-        'deleteText': ugettext('Delete'),
+        "prefix": formset.prefix,
+        "pkFieldName": formset.model._meta.pk.name,
+        "addText": getattr(formset, "add_text", None)
+        or ugettext("Add another %(verbose_name)s")
+        % {"verbose_name": capfirst(verbose_name)},
+        "showAddButton": getattr(formset, "show_add_button", True),
+        "deleteText": ugettext("Delete"),
     }
 
     if isinstance(formset, BasePolymorphicModelFormSet):
         # Allow to add different types
-        options['childTypes'] = [
+        options["childTypes"] = [
             {
-                'name': force_text(model._meta.verbose_name),
-                'type': model._meta.model_name,
-            } for model in formset.child_forms.keys()
+                "name": force_text(model._meta.verbose_name),
+                "type": model._meta.model_name,
+            }
+            for model in formset.child_forms.keys()
         ]
 
     return json.dumps(options)

polymorphic/tests/admintestcase.py

@@ -12,6 +12,7 @@ class AdminTestCase(TestCase):
     """
     Testing the admin site
     """
+
     #: The model to test
     model = None
     #: The admin class to test
@@ -20,7 +21,9 @@ class AdminTestCase(TestCase):
     @classmethod
     def setUpClass(cls):
         super(AdminTestCase, cls).setUpClass()
-        cls.admin_user = User.objects.create_superuser('admin', 'admin@example.org', password='admin')
+        cls.admin_user = User.objects.create_superuser(
+            "admin", "admin@example.org", password="admin"
+        )
 
     def setUp(self):
         super(AdminTestCase, self).setUp()
@@ -37,9 +40,11 @@ class AdminTestCase(TestCase):
 
     def register(self, model):
         """Decorator, like admin.register()"""
+
         def _dec(admin_class):
             self.admin_register(model, admin_class)
             return admin_class
+
         return _dec
 
     def admin_register(self, model, admin_site):
@@ -48,9 +53,7 @@ class AdminTestCase(TestCase):
 
         # Make sure the URLs are reachable by reverse()
         clear_url_caches()
-        set_urlconf(tuple([
-            url('^tmp-admin/', self.admin_site.urls)
-        ]))
+        set_urlconf(tuple([url("^tmp-admin/", self.admin_site.urls)]))
 
     def get_admin_instance(self, model):
         try:
@@ -66,40 +69,42 @@ class AdminTestCase(TestCase):
 
     def get_add_url(self, model):
         admin_instance = self.get_admin_instance(model)
-        return reverse(admin_urlname(admin_instance.opts, 'add'))
+        return reverse(admin_urlname(admin_instance.opts, "add"))
 
     def get_changelist_url(self, model):
         admin_instance = self.get_admin_instance(model)
-        return reverse(admin_urlname(admin_instance.opts, 'changelist'))
+        return reverse(admin_urlname(admin_instance.opts, "changelist"))
 
     def get_change_url(self, model, object_id):
         admin_instance = self.get_admin_instance(model)
-        return reverse(admin_urlname(admin_instance.opts, 'change'), args=(object_id,))
+        return reverse(admin_urlname(admin_instance.opts, "change"), args=(object_id,))
 
     def get_history_url(self, model, object_id):
         admin_instance = self.get_admin_instance(model)
-        return reverse(admin_urlname(admin_instance.opts, 'history'), args=(object_id,))
+        return reverse(admin_urlname(admin_instance.opts, "history"), args=(object_id,))
 
     def get_delete_url(self, model, object_id):
         admin_instance = self.get_admin_instance(model)
-        return reverse(admin_urlname(admin_instance.opts, 'delete'), args=(object_id,))
+        return reverse(admin_urlname(admin_instance.opts, "delete"), args=(object_id,))
 
-    def admin_get_add(self, model, qs=''):
+    def admin_get_add(self, model, qs=""):
         """
         Make a direct "add" call to the admin page, circumvening login checks.
         """
         admin_instance = self.get_admin_instance(model)
-        request = self.create_admin_request('get', self.get_add_url(model) + qs)
+        request = self.create_admin_request("get", self.get_add_url(model) + qs)
         response = admin_instance.add_view(request)
         self.assertEqual(response.status_code, 200)
         return response
 
-    def admin_post_add(self, model, formdata, qs=''):
+    def admin_post_add(self, model, formdata, qs=""):
         """
         Make a direct "add" call to the admin page, circumvening login checks.
         """
         admin_instance = self.get_admin_instance(model)
-        request = self.create_admin_request('post', self.get_add_url(model) + qs, data=formdata)
+        request = self.create_admin_request(
+            "post", self.get_add_url(model) + qs, data=formdata
+        )
         response = admin_instance.add_view(request)
         self.assertFormSuccess(request.path, response)
         return response
@@ -109,7 +114,7 @@ class AdminTestCase(TestCase):
         Make a direct "add" call to the admin page, circumvening login checks.
         """
         admin_instance = self.get_admin_instance(model)
-        request = self.create_admin_request('get', self.get_changelist_url(model))
+        request = self.create_admin_request("get", self.get_changelist_url(model))
         response = admin_instance.changelist_view(request)
         self.assertEqual(response.status_code, 200)
         return response
@@ -119,7 +124,9 @@ class AdminTestCase(TestCase):
         Perform a GET request on the admin page
         """
         admin_instance = self.get_admin_instance(model)
-        request = self.create_admin_request('get', self.get_change_url(model, object_id), data=query, **extra)
+        request = self.create_admin_request(
+            "get", self.get_change_url(model, object_id), data=query, **extra
+        )
         response = admin_instance.change_view(request, str(object_id))
         self.assertEqual(response.status_code, 200)
         return response
@@ -129,7 +136,9 @@ class AdminTestCase(TestCase):
         Make a direct "add" call to the admin page, circumvening login checks.
         """
         admin_instance = self.get_admin_instance(model)
-        request = self.create_admin_request('post', self.get_change_url(model, object_id), data=formdata, **extra)
+        request = self.create_admin_request(
+            "post", self.get_change_url(model, object_id), data=formdata, **extra
+        )
         response = admin_instance.change_view(request, str(object_id))
         self.assertFormSuccess(request.path, response)
         return response
@@ -139,7 +148,9 @@ class AdminTestCase(TestCase):
         Perform a GET request on the admin page
         """
         admin_instance = self.get_admin_instance(model)
-        request = self.create_admin_request('get', self.get_history_url(model, object_id), data=query, **extra)
+        request = self.create_admin_request(
+            "get", self.get_history_url(model, object_id), data=query, **extra
+        )
         response = admin_instance.history_view(request, str(object_id))
         self.assertEqual(response.status_code, 200)
         return response
@@ -149,7 +160,9 @@ class AdminTestCase(TestCase):
         Perform a GET request on the admin delete page
         """
         admin_instance = self.get_admin_instance(model)
-        request = self.create_admin_request('get', self.get_delete_url(model, object_id), data=query, **extra)
+        request = self.create_admin_request(
+            "get", self.get_delete_url(model, object_id), data=query, **extra
+        )
         response = admin_instance.delete_view(request, str(object_id))
         self.assertEqual(response.status_code, 200)
         return response
@@ -159,12 +172,16 @@ class AdminTestCase(TestCase):
         Make a direct "add" call to the admin page, circumvening login checks.
         """
         if not extra:
-            extra = {'data': {'post': 'yes'}}
+            extra = {"data": {"post": "yes"}}
 
         admin_instance = self.get_admin_instance(model)
-        request = self.create_admin_request('post', self.get_delete_url(model, object_id), **extra)
+        request = self.create_admin_request(
+            "post", self.get_delete_url(model, object_id), **extra
+        )
         response = admin_instance.delete_view(request, str(object_id))
-        self.assertEqual(response.status_code, 302, "Form errors in calling {0}".format(request.path))
+        self.assertEqual(
+            response.status_code, 302, "Form errors in calling {0}".format(request.path)
+        )
         return response
 
     def create_admin_request(self, method, url, data=None, **extra):
@@ -174,8 +191,8 @@ class AdminTestCase(TestCase):
         factory_method = getattr(RequestFactory(), method)
 
         if data is not None:
-            if method != 'get':
-                data['csrfmiddlewaretoken'] = 'foo'
+            if method != "get":
+                data["csrfmiddlewaretoken"] = "foo"
             dummy_request = factory_method(url, data=data)
             dummy_request.user = self.admin_user
 
@@ -185,7 +202,7 @@ class AdminTestCase(TestCase):
             # data = base_data
 
         request = factory_method(url, data=data, **extra)
-        request.COOKIES[settings.CSRF_COOKIE_NAME] = 'foo'
+        request.COOKIES[settings.CSRF_COOKIE_NAME] = "foo"
         request.csrf_processing_done = True
 
         # Add properties which middleware would typically do
@@ -201,14 +218,21 @@ class AdminTestCase(TestCase):
         self.assertIn(response.status_code, [200, 302])
         if response.status_code != 302:
             context_data = response.context_data
-            if 'errors' in context_data:
-                errors = response.context_data['errors']
-            elif 'form' in context_data:
-                errors = context_data['form'].errors
+            if "errors" in context_data:
+                errors = response.context_data["errors"]
+            elif "form" in context_data:
+                errors = context_data["form"].errors
             else:
                 raise KeyError("Unknown field for errors in the TemplateResponse!")
 
-            self.assertEqual(response.status_code, 302,
-                             "Form errors in calling {0}:\n{1}".format(request_url, errors.as_text()))
-        self.assertTrue('/login/?next=' not in response['Location'],
-                        "Received login response for {0}".format(request_url))
+            self.assertEqual(
+                response.status_code,
+                302,
+                "Form errors in calling {0}:\n{1}".format(
+                    request_url, errors.as_text()
+                ),
+            )
+        self.assertTrue(
+            "/login/?next=" not in response["Location"],
+            "Received login response for {0}".format(request_url),
+        )

polymorphic/tests/models.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
-import django
 import uuid
 
+import django
 from django.contrib.contenttypes.models import ContentType
 from django.db import models
 from django.db.models.query import QuerySet
@@ -9,7 +9,11 @@ from django.db.models.query import QuerySet
 from polymorphic.managers import PolymorphicManager
 from polymorphic.models import PolymorphicModel
 from polymorphic.query import PolymorphicQuerySet
-from polymorphic.showfields import ShowFieldContent, ShowFieldType, ShowFieldTypeAndContent
+from polymorphic.showfields import (
+    ShowFieldContent,
+    ShowFieldType,
+    ShowFieldTypeAndContent,
+)
 
 
 class PlainA(models.Model):
@@ -59,17 +63,17 @@ class ModelExtraExternal(models.Model):
 
 class ModelShow1(ShowFieldType, PolymorphicModel):
     field1 = models.CharField(max_length=10)
-    m2m = models.ManyToManyField('self')
+    m2m = models.ManyToManyField("self")
 
 
 class ModelShow2(ShowFieldContent, PolymorphicModel):
     field1 = models.CharField(max_length=10)
-    m2m = models.ManyToManyField('self')
+    m2m = models.ManyToManyField("self")
 
 
 class ModelShow3(ShowFieldTypeAndContent, PolymorphicModel):
     field1 = models.CharField(max_length=10)
-    m2m = models.ManyToManyField('self')
+    m2m = models.ManyToManyField("self")
 
 
 class ModelShow1_plain(PolymorphicModel):
@@ -108,8 +112,10 @@ class Enhance_Inherit(Enhance_Base, Enhance_Plain):
 
 class RelationBase(ShowFieldTypeAndContent, PolymorphicModel):
     field_base = models.CharField(max_length=10)
-    fk = models.ForeignKey('self', on_delete=models.CASCADE, null=True, related_name='relationbase_set')
-    m2m = models.ManyToManyField('self')
+    fk = models.ForeignKey(
+        "self", on_delete=models.CASCADE, null=True, related_name="relationbase_set"
+    )
+    m2m = models.ManyToManyField("self")
 
 
 class RelationA(RelationBase):
@@ -143,21 +149,24 @@ class ModelUnderRelParent(PolymorphicModel):
 
 
 class ModelUnderRelChild(PolymorphicModel):
-    parent = models.ForeignKey(ModelUnderRelParent, on_delete=models.CASCADE, related_name='children')
+    parent = models.ForeignKey(
+        ModelUnderRelParent, on_delete=models.CASCADE, related_name="children"
+    )
     _private2 = models.CharField(max_length=10)
 
 
 class MyManagerQuerySet(PolymorphicQuerySet):
-
     def my_queryset_foo(self):
-        return self.all()  # Just a method to prove the existance of the custom queryset.
+        return (
+            self.all()
+        )  # Just a method to prove the existance of the custom queryset.
 
 
 class MyManager(PolymorphicManager):
     queryset_class = MyManagerQuerySet
 
     def get_queryset(self):
-        return super(MyManager, self).get_queryset().order_by('-field1')
+        return super(MyManager, self).get_queryset().order_by("-field1")
 
     def my_queryset_foo(self):
         return self.all().my_queryset_foo()
@@ -196,12 +205,15 @@ class MROBase2(MROBase1):
 
 
 class MROBase3(models.Model):
-    base_3_id = models.AutoField(primary_key=True)   # make sure 'id' field doesn't clash, detected by Django 1.11
+    base_3_id = models.AutoField(
+        primary_key=True
+    )  # make sure 'id' field doesn't clash, detected by Django 1.11
     objects = models.Manager()
 
 
 class MRODerived(MROBase2, MROBase3):
     if django.VERSION < (3, 0):
+
         class Meta:
             manager_inheritance_from_future = True
 
@@ -212,18 +224,20 @@ class ParentModelWithManager(PolymorphicModel):
 
 class ChildModelWithManager(PolymorphicModel):
     # Also test whether foreign keys receive the manager:
-    fk = models.ForeignKey(ParentModelWithManager, on_delete=models.CASCADE, related_name='childmodel_set')
+    fk = models.ForeignKey(
+        ParentModelWithManager, on_delete=models.CASCADE, related_name="childmodel_set"
+    )
     objects = MyManager()
 
 
 class PlainMyManagerQuerySet(QuerySet):
-
     def my_queryset_foo(self):
-        return self.all()  # Just a method to prove the existence of the custom queryset.
+        return (
+            self.all()
+        )  # Just a method to prove the existence of the custom queryset.
 
 
 class PlainMyManager(models.Manager):
-
     def my_queryset_foo(self):
         return self.get_queryset().my_queryset_foo()
 
@@ -236,7 +250,11 @@ class PlainParentModelWithManager(models.Model):
 
 
 class PlainChildModelWithManager(models.Model):
-    fk = models.ForeignKey(PlainParentModelWithManager, on_delete=models.CASCADE, related_name='childmodel_set')
+    fk = models.ForeignKey(
+        PlainParentModelWithManager,
+        on_delete=models.CASCADE,
+        related_name="childmodel_set",
+    )
     objects = PlainMyManager()
 
 
@@ -270,14 +288,14 @@ class InitTestModel(ShowFieldType, PolymorphicModel):
     bar = models.CharField(max_length=100)
 
     def __init__(self, *args, **kwargs):
-        kwargs['bar'] = self.x()
+        kwargs["bar"] = self.x()
         super(InitTestModel, self).__init__(*args, **kwargs)
 
 
 class InitTestModelSubclass(InitTestModel):
-
     def x(self):
-        return 'XYZ'
+        return "XYZ"
+
 
 # models from github issue
 
@@ -319,6 +337,7 @@ class UUIDPlainB(UUIDPlainA):
 class UUIDPlainC(UUIDPlainB):
     field3 = models.CharField(max_length=10)
 
+
 # base -> proxy
 
 
@@ -327,7 +346,6 @@ class ProxyBase(PolymorphicModel):
 
 
 class ProxyChild(ProxyBase):
-
     class Meta:
         proxy = True
 
@@ -335,6 +353,7 @@ class ProxyChild(ProxyBase):
 class NonProxyChild(ProxyBase):
     name = models.CharField(max_length=10)
 
+
 # base -> proxy -> real models
 
 
@@ -343,7 +362,6 @@ class ProxiedBase(ShowFieldTypeAndContent, PolymorphicModel):
 
 
 class ProxyModelBase(ProxiedBase):
-
     class Meta:
         proxy = True
 
@@ -364,14 +382,20 @@ class ProxyModelB(ProxyModelBase):
 # with related field 'ContentType.relatednameclash_set'." (reported by Andrew Ingram)
 # fixed with related_name
 class RelatedNameClash(ShowFieldType, PolymorphicModel):
-    ctype = models.ForeignKey(ContentType, on_delete=models.CASCADE, null=True, editable=False)
+    ctype = models.ForeignKey(
+        ContentType, on_delete=models.CASCADE, null=True, editable=False
+    )
+
 
 # class with a parent_link to superclass, and a related_name back to subclass
 
 
 class TestParentLinkAndRelatedName(ModelShow1_plain):
     superclass = models.OneToOneField(
-        ModelShow1_plain, on_delete=models.CASCADE, parent_link=True, related_name='related_name_subclass'
+        ModelShow1_plain,
+        on_delete=models.CASCADE,
+        parent_link=True,
+        related_name="related_name_subclass",
     )
 
 
@@ -398,7 +422,7 @@ class AbstractModel(PolymorphicModel):
 
 class SwappableModel(AbstractModel):
     class Meta:
-        swappable = 'POLYMORPHIC_TEST_SWAPPABLE'
+        swappable = "POLYMORPHIC_TEST_SWAPPABLE"
 
 
 class SwappedModel(AbstractModel):
@@ -410,7 +434,9 @@ class InlineParent(models.Model):
 
 
 class InlineModelA(PolymorphicModel):
-    parent = models.ForeignKey(InlineParent, related_name='inline_children', on_delete=models.CASCADE)
+    parent = models.ForeignKey(
+        InlineParent, related_name="inline_children", on_delete=models.CASCADE
+    )
     field1 = models.CharField(max_length=10)
 
 
@@ -434,13 +460,11 @@ class Duck(PolymorphicModel):
 
 
 class RedheadDuck(Duck):
-
     class Meta:
         proxy = True
 
 
 class RubberDuck(Duck):
-
     class Meta:
         proxy = True
 
@@ -454,22 +478,22 @@ class MultiTableDerived(MultiTableBase):
 
 
 class SubclassSelectorAbstractBaseModel(PolymorphicModel):
-    base_field = models.CharField(max_length=10, default='test_bf')
+    base_field = models.CharField(max_length=10, default="test_bf")
 
 
 class SubclassSelectorAbstractModel(SubclassSelectorAbstractBaseModel):
-    abstract_field = models.CharField(max_length=10, default='test_af')
+    abstract_field = models.CharField(max_length=10, default="test_af")
 
     class Meta:
         abstract = True
 
 
 class SubclassSelectorAbstractConcreteModel(SubclassSelectorAbstractModel):
-    concrete_field = models.CharField(max_length=10, default='test_cf')
+    concrete_field = models.CharField(max_length=10, default="test_cf")
 
 
 class SubclassSelectorProxyBaseModel(PolymorphicModel):
-    base_field = models.CharField(max_length=10, default='test_bf')
+    base_field = models.CharField(max_length=10, default="test_bf")
 
 
 class SubclassSelectorProxyModel(SubclassSelectorProxyBaseModel):
@@ -478,4 +502,4 @@ class SubclassSelectorProxyModel(SubclassSelectorProxyBaseModel):
 
 
 class SubclassSelectorProxyConcreteModel(SubclassSelectorProxyModel):
-    concrete_field = models.CharField(max_length=10, default='test_cf')
+    concrete_field = models.CharField(max_length=10, default="test_cf")

polymorphic/tests/test_admin.py

@@ -2,18 +2,31 @@ from django.contrib import admin
 from django.contrib.contenttypes.models import ContentType
 from django.utils.html import escape
 
-from polymorphic.admin import PolymorphicChildModelAdmin, PolymorphicChildModelFilter, PolymorphicInlineSupportMixin, \
-    PolymorphicParentModelAdmin, StackedPolymorphicInline
+from polymorphic.admin import (
+    PolymorphicChildModelAdmin,
+    PolymorphicChildModelFilter,
+    PolymorphicInlineSupportMixin,
+    PolymorphicParentModelAdmin,
+    StackedPolymorphicInline,
+)
 from polymorphic.tests.admintestcase import AdminTestCase
-from polymorphic.tests.models import InlineModelA, InlineModelB, InlineParent, Model2A, Model2B, Model2C, Model2D
+from polymorphic.tests.models import (
+    InlineModelA,
+    InlineModelB,
+    InlineParent,
+    Model2A,
+    Model2B,
+    Model2C,
+    Model2D,
+)
 
 
 class PolymorphicAdminTests(AdminTestCase):
-
     def test_admin_registration(self):
         """
         Test how the registration works
         """
+
         @self.register(Model2A)
         class Model2Admin(PolymorphicParentModelAdmin):
             base_model = Model2A
@@ -25,48 +38,42 @@ class PolymorphicAdminTests(AdminTestCase):
         @self.register(Model2D)
         class Model2ChildAdmin(PolymorphicChildModelAdmin):
             base_model = Model2A
-            base_fieldsets = (
-                ("Base fields", {
-                    'fields': ('field1',)
-                }),
-            )
+            base_fieldsets = (("Base fields", {"fields": ("field1",)}),)
 
         # -- add page
         ct_id = ContentType.objects.get_for_model(Model2D).pk
         self.admin_get_add(Model2A)  # shows type page
-        self.admin_get_add(Model2A, qs='?ct_id={}'.format(ct_id))  # shows type page
+        self.admin_get_add(Model2A, qs="?ct_id={}".format(ct_id))  # shows type page
 
         self.admin_get_add(Model2A)  # shows type page
-        self.admin_post_add(Model2A, {
-            'field1': 'A',
-            'field2': 'B',
-            'field3': 'C',
-            'field4': 'D'
-        }, qs='?ct_id={}'.format(ct_id))
+        self.admin_post_add(
+            Model2A,
+            {"field1": "A", "field2": "B", "field3": "C", "field4": "D"},
+            qs="?ct_id={}".format(ct_id),
+        )
 
         d_obj = Model2A.objects.all()[0]
         self.assertEqual(d_obj.__class__, Model2D)
-        self.assertEqual(d_obj.field1, 'A')
-        self.assertEqual(d_obj.field2, 'B')
+        self.assertEqual(d_obj.field1, "A")
+        self.assertEqual(d_obj.field2, "B")
 
         # -- list page
         self.admin_get_changelist(Model2A)  # asserts 200
 
         # -- edit
         response = self.admin_get_change(Model2A, d_obj.pk)
-        self.assertContains(response, 'field4')
-        self.admin_post_change(Model2A, d_obj.pk, {
-            'field1': 'A2',
-            'field2': 'B2',
-            'field3': 'C2',
-            'field4': 'D2'
-        })
+        self.assertContains(response, "field4")
+        self.admin_post_change(
+            Model2A,
+            d_obj.pk,
+            {"field1": "A2", "field2": "B2", "field3": "C2", "field4": "D2"},
+        )
 
         d_obj.refresh_from_db()
-        self.assertEqual(d_obj.field1, 'A2')
-        self.assertEqual(d_obj.field2, 'B2')
-        self.assertEqual(d_obj.field3, 'C2')
-        self.assertEqual(d_obj.field4, 'D2')
+        self.assertEqual(d_obj.field1, "A2")
+        self.assertEqual(d_obj.field2, "B2")
+        self.assertEqual(d_obj.field3, "C2")
+        self.assertEqual(d_obj.field4, "D2")
 
         # -- history
         self.admin_get_history(Model2A, d_obj.pk)
@@ -80,6 +87,7 @@ class PolymorphicAdminTests(AdminTestCase):
         """
         Test the registration of inline models.
         """
+
         class InlineModelAChild(StackedPolymorphicInline.Child):
             model = InlineModelA
 
@@ -88,43 +96,46 @@ class PolymorphicAdminTests(AdminTestCase):
 
         class Inline(StackedPolymorphicInline):
             model = InlineModelA
-            child_inlines = (
-                InlineModelAChild,
-                InlineModelBChild,
-            )
+            child_inlines = (InlineModelAChild, InlineModelBChild)
 
         @self.register(InlineParent)
         class InlineParentAdmin(PolymorphicInlineSupportMixin, admin.ModelAdmin):
             inlines = (Inline,)
 
-        parent = InlineParent.objects.create(title='FOO')
+        parent = InlineParent.objects.create(title="FOO")
         self.assertEqual(parent.inline_children.count(), 0)
 
         # -- get edit page
         response = self.admin_get_change(InlineParent, parent.pk)
 
         # Make sure the fieldset has the right data exposed in data-inline-formset
-        self.assertContains(response, 'childTypes')
+        self.assertContains(response, "childTypes")
         self.assertContains(response, escape('"type": "inlinemodela"'))
         self.assertContains(response, escape('"type": "inlinemodelb"'))
 
         # -- post edit page
-        self.admin_post_change(InlineParent, parent.pk, {
-            'title': 'FOO2',
-            'inline_children-INITIAL_FORMS': 0,
-            'inline_children-TOTAL_FORMS': 1,
-            'inline_children-MIN_NUM_FORMS': 0,
-            'inline_children-MAX_NUM_FORMS': 1000,
-            'inline_children-0-parent': parent.pk,
-            'inline_children-0-polymorphic_ctype': ContentType.objects.get_for_model(InlineModelB).pk,
-            'inline_children-0-field1': 'A2',
-            'inline_children-0-field2': 'B2',
-        })
+        self.admin_post_change(
+            InlineParent,
+            parent.pk,
+            {
+                "title": "FOO2",
+                "inline_children-INITIAL_FORMS": 0,
+                "inline_children-TOTAL_FORMS": 1,
+                "inline_children-MIN_NUM_FORMS": 0,
+                "inline_children-MAX_NUM_FORMS": 1000,
+                "inline_children-0-parent": parent.pk,
+                "inline_children-0-polymorphic_ctype": ContentType.objects.get_for_model(
+                    InlineModelB
+                ).pk,
+                "inline_children-0-field1": "A2",
+                "inline_children-0-field2": "B2",
+            },
+        )
 
         parent.refresh_from_db()
-        self.assertEqual(parent.title, 'FOO2')
+        self.assertEqual(parent.title, "FOO2")
         self.assertEqual(parent.inline_children.count(), 1)
         child = parent.inline_children.all()[0]
         self.assertEqual(child.__class__, InlineModelB)
-        self.assertEqual(child.field1, 'A2')
-        self.assertEqual(child.field2, 'B2')
+        self.assertEqual(child.field1, "A2")
+        self.assertEqual(child.field2, "B2")

polymorphic/tests/test_contrib.py

@@ -1,10 +1,7 @@
 from unittest import TestCase
 
 from polymorphic.contrib.guardian import get_polymorphic_base_content_type
-from polymorphic.tests.models import (
-    Model2D,
-    PlainC,
-)
+from polymorphic.tests.models import Model2D, PlainC
 
 
 class ContribTests(TestCase):
@@ -12,20 +9,19 @@ class ContribTests(TestCase):
     The test suite
     """
 
-
     def test_contrib_guardian(self):
         # Regular Django inheritance should return the child model content type.
         obj = PlainC()
         ctype = get_polymorphic_base_content_type(obj)
-        self.assertEqual(ctype.name, 'plain c')
+        self.assertEqual(ctype.name, "plain c")
 
         ctype = get_polymorphic_base_content_type(PlainC)
-        self.assertEqual(ctype.name, 'plain c')
+        self.assertEqual(ctype.name, "plain c")
 
         # Polymorphic inheritance should return the parent model content type.
         obj = Model2D()
         ctype = get_polymorphic_base_content_type(obj)
-        self.assertEqual(ctype.name, 'model2a')
+        self.assertEqual(ctype.name, "model2a")
 
         ctype = get_polymorphic_base_content_type(Model2D)
-        self.assertEqual(ctype.name, 'model2a')
+        self.assertEqual(ctype.name, "model2a")

polymorphic/tests/test_multidb.py

@@ -23,29 +23,29 @@ class MultipleDatabasesTests(TestCase):
     multi_db = True
 
     def test_save_to_non_default_database(self):
-        Model2A.objects.db_manager('secondary').create(field1='A1')
-        Model2C(field1='C1', field2='C2', field3='C3').save(using='secondary')
-        Model2B.objects.create(field1='B1', field2='B2')
-        Model2D(field1='D1', field2='D2', field3='D3', field4='D4').save()
+        Model2A.objects.db_manager("secondary").create(field1="A1")
+        Model2C(field1="C1", field2="C2", field3="C3").save(using="secondary")
+        Model2B.objects.create(field1="B1", field2="B2")
+        Model2D(field1="D1", field2="D2", field3="D3", field4="D4").save()
 
         self.assertQuerysetEqual(
-            Model2A.objects.order_by('id'),
+            Model2A.objects.order_by("id"),
             [Model2B, Model2D],
             transform=lambda o: o.__class__,
         )
 
         self.assertQuerysetEqual(
-            Model2A.objects.db_manager('secondary').order_by('id'),
+            Model2A.objects.db_manager("secondary").order_by("id"),
             [Model2A, Model2C],
             transform=lambda o: o.__class__,
         )
 
     def test_instance_of_filter_on_non_default_database(self):
-        Base.objects.db_manager('secondary').create(field_b='B1')
-        ModelX.objects.db_manager('secondary').create(field_b='B', field_x='X')
-        ModelY.objects.db_manager('secondary').create(field_b='Y', field_y='Y')
+        Base.objects.db_manager("secondary").create(field_b="B1")
+        ModelX.objects.db_manager("secondary").create(field_b="B", field_x="X")
+        ModelY.objects.db_manager("secondary").create(field_b="Y", field_y="Y")
 
-        objects = Base.objects.db_manager('secondary').filter(instance_of=Base)
+        objects = Base.objects.db_manager("secondary").filter(instance_of=Base)
         self.assertQuerysetEqual(
             objects,
             [Base, ModelX, ModelY],
@@ -54,19 +54,19 @@ class MultipleDatabasesTests(TestCase):
         )
 
         self.assertQuerysetEqual(
-            Base.objects.db_manager('secondary').filter(instance_of=ModelX),
+            Base.objects.db_manager("secondary").filter(instance_of=ModelX),
             [ModelX],
             transform=lambda o: o.__class__,
         )
 
         self.assertQuerysetEqual(
-            Base.objects.db_manager('secondary').filter(instance_of=ModelY),
+            Base.objects.db_manager("secondary").filter(instance_of=ModelY),
             [ModelY],
             transform=lambda o: o.__class__,
         )
 
         self.assertQuerysetEqual(
-            Base.objects.db_manager('secondary').filter(
+            Base.objects.db_manager("secondary").filter(
                 Q(instance_of=ModelX) | Q(instance_of=ModelY)
             ),
             [ModelX, ModelY],
@@ -76,10 +76,14 @@ class MultipleDatabasesTests(TestCase):
 
     def test_forward_many_to_one_descriptor_on_non_default_database(self):
         def func():
-            blog = BlogA.objects.db_manager('secondary').create(name='Blog', info='Info')
-            entry = BlogEntry.objects.db_manager('secondary').create(blog=blog, text='Text')
+            blog = BlogA.objects.db_manager("secondary").create(
+                name="Blog", info="Info"
+            )
+            entry = BlogEntry.objects.db_manager("secondary").create(
+                blog=blog, text="Text"
+            )
             ContentType.objects.clear_cache()
-            entry = BlogEntry.objects.db_manager('secondary').get(pk=entry.id)
+            entry = BlogEntry.objects.db_manager("secondary").get(pk=entry.id)
             self.assertEqual(blog, entry.blog)
 
         # Ensure no queries are made using the default database.
@@ -87,21 +91,27 @@ class MultipleDatabasesTests(TestCase):
 
     def test_reverse_many_to_one_descriptor_on_non_default_database(self):
         def func():
-            blog = BlogA.objects.db_manager('secondary').create(name='Blog', info='Info')
-            entry = BlogEntry.objects.db_manager('secondary').create(blog=blog, text='Text')
+            blog = BlogA.objects.db_manager("secondary").create(
+                name="Blog", info="Info"
+            )
+            entry = BlogEntry.objects.db_manager("secondary").create(
+                blog=blog, text="Text"
+            )
             ContentType.objects.clear_cache()
-            blog = BlogA.objects.db_manager('secondary').get(pk=blog.id)
-            self.assertEqual(entry, blog.blogentry_set.using('secondary').get())
+            blog = BlogA.objects.db_manager("secondary").get(pk=blog.id)
+            self.assertEqual(entry, blog.blogentry_set.using("secondary").get())
 
         # Ensure no queries are made using the default database.
         self.assertNumQueries(0, func)
 
     def test_reverse_one_to_one_descriptor_on_non_default_database(self):
         def func():
-            m2a = Model2A.objects.db_manager('secondary').create(field1='A1')
-            one2one = One2OneRelatingModel.objects.db_manager('secondary').create(one2one=m2a, field1='121')
+            m2a = Model2A.objects.db_manager("secondary").create(field1="A1")
+            one2one = One2OneRelatingModel.objects.db_manager("secondary").create(
+                one2one=m2a, field1="121"
+            )
             ContentType.objects.clear_cache()
-            m2a = Model2A.objects.db_manager('secondary').get(pk=m2a.id)
+            m2a = Model2A.objects.db_manager("secondary").get(pk=m2a.id)
             self.assertEqual(one2one, m2a.one2onerelatingmodel)
 
         # Ensure no queries are made using the default database.
@@ -109,12 +119,12 @@ class MultipleDatabasesTests(TestCase):
 
     def test_many_to_many_descriptor_on_non_default_database(self):
         def func():
-            m2a = Model2A.objects.db_manager('secondary').create(field1='A1')
-            rm = RelatingModel.objects.db_manager('secondary').create()
+            m2a = Model2A.objects.db_manager("secondary").create(field1="A1")
+            rm = RelatingModel.objects.db_manager("secondary").create()
             rm.many2many.add(m2a)
             ContentType.objects.clear_cache()
-            m2a = Model2A.objects.db_manager('secondary').get(pk=m2a.id)
-            self.assertEqual(rm, m2a.relatingmodel_set.using('secondary').get())
+            m2a = Model2A.objects.db_manager("secondary").get(pk=m2a.id)
+            self.assertEqual(rm, m2a.relatingmodel_set.using("secondary").get())
 
         # Ensure no queries are made using the default database.
         self.assertNumQueries(0, func)

polymorphic/tests/test_regression.py

@@ -1,9 +1,9 @@
 from django.test import TestCase
+
 from polymorphic.tests.models import Bottom, Middle, Top
 
 
 class RegressionTests(TestCase):
-
     def test_for_query_result_incomplete_with_inheritance(self):
         """ https://github.com/bconstantin/django_polymorphic/issues/15 """
 
@@ -15,10 +15,16 @@ class RegressionTests(TestCase):
         bottom.save()
 
         expected_queryset = [top, middle, bottom]
-        self.assertQuerysetEqual(Top.objects.order_by('pk'), [repr(r) for r in expected_queryset])
+        self.assertQuerysetEqual(
+            Top.objects.order_by("pk"), [repr(r) for r in expected_queryset]
+        )
 
         expected_queryset = [middle, bottom]
-        self.assertQuerysetEqual(Middle.objects.order_by('pk'), [repr(r) for r in expected_queryset])
+        self.assertQuerysetEqual(
+            Middle.objects.order_by("pk"), [repr(r) for r in expected_queryset]
+        )
 
         expected_queryset = [bottom]
-        self.assertQuerysetEqual(Bottom.objects.order_by('pk'), [repr(r) for r in expected_queryset])
+        self.assertQuerysetEqual(
+            Bottom.objects.order_by("pk"), [repr(r) for r in expected_queryset]
+        )

polymorphic/tests/test_utils.py

@@ -1,26 +1,36 @@
 from django.test import TransactionTestCase
 
-from polymorphic.models import PolymorphicTypeUndefined, PolymorphicModel
-from polymorphic.tests.models import Model2A, Model2B, Model2C, Model2D, Enhance_Inherit, Enhance_Base
-from polymorphic.utils import reset_polymorphic_ctype, sort_by_subclass, get_base_polymorphic_model
+from polymorphic.models import PolymorphicModel, PolymorphicTypeUndefined
+from polymorphic.tests.models import (
+    Enhance_Base,
+    Enhance_Inherit,
+    Model2A,
+    Model2B,
+    Model2C,
+    Model2D,
+)
+from polymorphic.utils import (
+    get_base_polymorphic_model,
+    reset_polymorphic_ctype,
+    sort_by_subclass,
+)
 
 
 class UtilsTests(TransactionTestCase):
-
     def test_sort_by_subclass(self):
         self.assertEqual(
             sort_by_subclass(Model2D, Model2B, Model2D, Model2A, Model2C),
-            [Model2A, Model2B, Model2C, Model2D, Model2D]
+            [Model2A, Model2B, Model2C, Model2D, Model2D],
         )
 
     def test_reset_polymorphic_ctype(self):
         """
         Test the the polymorphic_ctype_id can be restored.
         """
-        Model2A.objects.create(field1='A1')
-        Model2D.objects.create(field1='A1', field2='B2', field3='C3', field4='D4')
-        Model2B.objects.create(field1='A1', field2='B2')
-        Model2B.objects.create(field1='A1', field2='B2')
+        Model2A.objects.create(field1="A1")
+        Model2D.objects.create(field1="A1", field2="B2", field3="C3", field4="D4")
+        Model2B.objects.create(field1="A1", field2="B2")
+        Model2B.objects.create(field1="A1", field2="B2")
         Model2A.objects.all().update(polymorphic_ctype_id=None)
 
         with self.assertRaises(PolymorphicTypeUndefined):
@@ -30,12 +40,7 @@ class UtilsTests(TransactionTestCase):
 
         self.assertQuerysetEqual(
             Model2A.objects.order_by("pk"),
-            [
-                Model2A,
-                Model2D,
-                Model2B,
-                Model2B,
-            ],
+            [Model2A, Model2D, Model2B, Model2B],
             transform=lambda o: o.__class__,
         )
 
@@ -59,6 +64,7 @@ class UtilsTests(TransactionTestCase):
         """
         Skipping abstract models that can't be used for querying.
         """
+
         class A(PolymorphicModel):
             class Meta:
                 abstract = True

polymorphic/utils.py

@@ -2,9 +2,9 @@ import sys
 
 from django.contrib.contenttypes.models import ContentType
 from django.db import DEFAULT_DB_ALIAS
-from polymorphic.models import PolymorphicModel
 
 from polymorphic.base import PolymorphicModelBase
+from polymorphic.models import PolymorphicModel
 
 
 def reset_polymorphic_ctype(*models, **filters):
@@ -16,8 +16,8 @@ def reset_polymorphic_ctype(*models, **filters):
     Add ``preserve_existing=True`` to skip models which already
     have a polymorphic content type.
     """
-    using = filters.pop('using', DEFAULT_DB_ALIAS)
-    ignore_existing = filters.pop('ignore_existing', False)
+    using = filters.pop("using", DEFAULT_DB_ALIAS)
+    ignore_existing = filters.pop("ignore_existing", False)
 
     models = sort_by_subclass(*models)
     if ignore_existing:
@@ -26,7 +26,9 @@ def reset_polymorphic_ctype(*models, **filters):
         models = reversed(models)
 
     for new_model in models:
-        new_ct = ContentType.objects.db_manager(using).get_for_model(new_model, for_concrete_model=False)
+        new_ct = ContentType.objects.db_manager(using).get_for_model(
+            new_model, for_concrete_model=False
+        )
 
         qs = new_model.objects.db_manager(using)
         if ignore_existing:
@@ -61,6 +63,7 @@ def sort_by_subclass(*classes):
         return sorted(classes, cmp=_compare_mro)
     else:
         from functools import cmp_to_key
+
         return sorted(classes, key=cmp_to_key(_compare_mro))
 
 
@@ -69,8 +72,10 @@ def get_base_polymorphic_model(ChildModel, allow_abstract=False):
     First the first concrete model in the inheritance chain that inherited from the PolymorphicModel.
     """
     for Model in reversed(ChildModel.mro()):
-        if isinstance(Model, PolymorphicModelBase) and \
-                Model is not PolymorphicModel and \
-                (allow_abstract or not Model._meta.abstract):
+        if (
+            isinstance(Model, PolymorphicModelBase)
+            and Model is not PolymorphicModel
+            and (allow_abstract or not Model._meta.abstract)
+        ):
             return Model
     return None

runtests.py

@@ -8,50 +8,51 @@ import django
 from django.conf import settings
 from django.core.management import execute_from_command_line
 
-
 # python -Wd, or run via coverage:
-warnings.simplefilter('always', DeprecationWarning)
+warnings.simplefilter("always", DeprecationWarning)
 
 # Give feedback on used versions
-sys.stderr.write('Using Python version {0} from {1}\n'.format(sys.version[:5], sys.executable))
-sys.stderr.write('Using Django version {0} from {1}\n'.format(
-    django.get_version(),
-    dirname(abspath(django.__file__)))
+sys.stderr.write(
+    "Using Python version {0} from {1}\n".format(sys.version[:5], sys.executable)
+)
+sys.stderr.write(
+    "Using Django version {0} from {1}\n".format(
+        django.get_version(), dirname(abspath(django.__file__))
+    )
 )
 
 if not settings.configured:
     settings.configure(
         DEBUG=False,
         DATABASES={
-            'default': dj_database_url.config(
-                env='PRIMARY_DATABASE',
-                default='sqlite://:memory:',
+            "default": dj_database_url.config(
+                env="PRIMARY_DATABASE", default="sqlite://:memory:"
             ),
-            'secondary': dj_database_url.config(
-                env='SECONDARY_DATABASE',
-                default='sqlite://:memory:',
+            "secondary": dj_database_url.config(
+                env="SECONDARY_DATABASE", default="sqlite://:memory:"
             ),
         },
         TEST_RUNNER="django.test.runner.DiscoverRunner",
         INSTALLED_APPS=(
-            'django.contrib.auth',
-            'django.contrib.contenttypes',
-            'django.contrib.messages',
-            'django.contrib.sessions',
-            'django.contrib.sites',
-            'django.contrib.admin',
-            'polymorphic',
-            'polymorphic.tests',
+            "django.contrib.auth",
+            "django.contrib.contenttypes",
+            "django.contrib.messages",
+            "django.contrib.sessions",
+            "django.contrib.sites",
+            "django.contrib.admin",
+            "polymorphic",
+            "polymorphic.tests",
         ),
         MIDDLEWARE=(
-            'django.middleware.common.CommonMiddleware',
-            'django.contrib.sessions.middleware.SessionMiddleware',
-            'django.middleware.csrf.CsrfViewMiddleware',
-            'django.contrib.auth.middleware.AuthenticationMiddleware',
-            'django.contrib.messages.middleware.MessageMiddleware',
+            "django.middleware.common.CommonMiddleware",
+            "django.contrib.sessions.middleware.SessionMiddleware",
+            "django.middleware.csrf.CsrfViewMiddleware",
+            "django.contrib.auth.middleware.AuthenticationMiddleware",
+            "django.contrib.messages.middleware.MessageMiddleware",
         ),
         SITE_ID=3,
-        TEMPLATES=[{
+        TEMPLATES=[
+            {
                 "BACKEND": "django.template.backends.django.DjangoTemplates",
                 "DIRS": (),
                 "OPTIONS": {
@@ -69,24 +70,25 @@ if not settings.configured:
                         "django.contrib.auth.context_processors.auth",
                     ),
                 },
-        },
+            }
         ],
-        POLYMORPHIC_TEST_SWAPPABLE='polymorphic.swappedmodel',
+        POLYMORPHIC_TEST_SWAPPABLE="polymorphic.swappedmodel",
         ROOT_URLCONF=None,
     )
 
 
-DEFAULT_TEST_APPS = [
-    'polymorphic',
-]
+DEFAULT_TEST_APPS = ["polymorphic"]
 
 
 def runtests():
-    other_args = list(filter(lambda arg: arg.startswith('-'), sys.argv[1:]))
-    test_apps = list(filter(lambda arg: not arg.startswith('-'), sys.argv[1:])) or DEFAULT_TEST_APPS
-    argv = sys.argv[:1] + ['test', '--traceback'] + other_args + test_apps
+    other_args = list(filter(lambda arg: arg.startswith("-"), sys.argv[1:]))
+    test_apps = (
+        list(filter(lambda arg: not arg.startswith("-"), sys.argv[1:]))
+        or DEFAULT_TEST_APPS
+    )
+    argv = sys.argv[:1] + ["test", "--traceback"] + other_args + test_apps
     execute_from_command_line(argv)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     runtests()

setup.py

@@ -2,5 +2,4 @@
 
 from setuptools import setup
 
-
 setup()