Fixed import error in the admin due to isort

polymorphic/admin/__init__.py

@@ -4,6 +4,8 @@ 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  # noqa
 from .childadmin import PolymorphicChildModelAdmin
 from .filters import PolymorphicChildModelFilter
 
@@ -23,9 +25,6 @@ from .helpers import PolymorphicInlineAdminForm, PolymorphicInlineAdminFormSet
 from .inlines import PolymorphicInlineModelAdmin  # base class
 from .inlines import StackedPolymorphicInline  # stacked inline
 
-# Admins for the regular models
-from .parentadmin import PolymorphicParentModelAdmin
-
 __all__ = (
     "PolymorphicParentModelAdmin",
     "PolymorphicChildModelAdmin",