Fix unicode attribute error if typing installed on py2.7 (#363)

src/drf_yasg/inspectors/field.py

@@ -2,6 +2,7 @@ import datetime
 import inspect
 import logging
 import operator
+import sys
 import uuid
 from collections import OrderedDict
 from decimal import Decimal
@@ -489,6 +490,9 @@ hinting_type_info = [
     (datetime.date, (openapi.TYPE_STRING, openapi.FORMAT_DATE)),
 ]
 
+if sys.version_info < (3, 0):
+    hinting_type_info.append((unicode, (openapi.TYPE_STRING, None)))
+
 if typing:
     def inspect_collection_hint_class(hint_class):
         args = hint_class.__args__

testproj/users/serializers.py

@@ -1,3 +1,5 @@
+import sys
+
 from django.contrib.auth.models import User
 from rest_framework import serializers
 
@@ -6,7 +8,10 @@ from snippets.models import Snippet
 
 try:
     import typing  # noqa: F401
+    if sys.version_info >= (3, 4):
         from .method_serializers_with_typing import MethodFieldExampleSerializer
+    else:
+        from .method_serializers_without_typing import MethodFieldExampleSerializer
 except ImportError:
     from .method_serializers_without_typing import MethodFieldExampleSerializer
 

tests/test_schema_generator.py

@@ -204,6 +204,7 @@ def test_action_mapping():
 
 @pytest.mark.parametrize('choices, expected_type', [
     (['A', 'B'], openapi.TYPE_STRING),
+    ([u'A', u'B'], openapi.TYPE_STRING),
     ([123, 456], openapi.TYPE_INTEGER),
     ([1.2, 3.4], openapi.TYPE_NUMBER),
     (['A', 456], openapi.TYPE_STRING)

tox.ini

@@ -5,6 +5,7 @@ isolated_build_env = .package
 
 # https://docs.djangoproject.com/en/dev/faq/install/#what-python-version-can-i-use-with-django
 envlist =
+    py27-django111-drf39-typing,
     py{27,34,35,36}-django111-drf{37,38,39},
     py{34,35,36,37}-django20-drf{37,38,39},
     py{35,36,37}-django21-drf{37,38,39},
@@ -26,6 +27,8 @@ deps =
     drf38: djangorestframework>=3.8.0,<3.9
     drf39: djangorestframework>=3.9,<3.10
 
+    typing: typing>=3.6.6
+
     # test with the latest build of django-rest-framework to get early warning of compatibility issues
     djmaster: https://github.com/encode/django-rest-framework/archive/master.tar.gz
     djmaster: https://github.com/django/django/archive/master.tar.gz