[1.8.x] Sorted imports with isort; refs #23860.

Backport of 0ed7d15563 from master

tests/postgres_tests/array_default_migrations/0001_initial.py

@@ -1,8 +1,8 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
 
-from django.db import models, migrations
 import django.contrib.postgres.fields
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):

tests/postgres_tests/array_default_migrations/0002_integerarraymodel_field_2.py

@@ -1,8 +1,8 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
 
-from django.db import models, migrations
 import django.contrib.postgres.fields
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):

tests/postgres_tests/migrations/0001_setup_extensions.py

@@ -1,7 +1,9 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
 
-from django.contrib.postgres.operations import HStoreExtension, UnaccentExtension
+from django.contrib.postgres.operations import (
+    HStoreExtension, UnaccentExtension,
+)
 from django.db import migrations
 
 

tests/postgres_tests/migrations/0002_create_test_models.py

@@ -1,9 +1,9 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
 
-from django.db import models, migrations
 import django.contrib.postgres.fields
 import django.contrib.postgres.fields.hstore
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):

tests/postgres_tests/models.py

@@ -1,6 +1,6 @@
 from django.contrib.postgres.fields import (
-    ArrayField, HStoreField, IntegerRangeField, BigIntegerRangeField,
-    FloatRangeField, DateTimeRangeField, DateRangeField,
+    ArrayField, BigIntegerRangeField, DateRangeField, DateTimeRangeField,
+    FloatRangeField, HStoreField, IntegerRangeField,
 )
 from django.db import connection, models
 

tests/postgres_tests/test_array.py

@@ -3,19 +3,18 @@ import json
 import unittest
 import uuid
 
+from django import forms
 from django.contrib.postgres.fields import ArrayField
 from django.contrib.postgres.forms import SimpleArrayField, SplitArrayField
 from django.core import exceptions, serializers
 from django.core.management import call_command
-from django.db import models, IntegrityError, connection
-from django import forms
+from django.db import IntegrityError, connection, models
 from django.test import TestCase, override_settings
 from django.utils import timezone
 
 from .models import (
-    IntegerArrayModel, NullableIntegerArrayModel, CharArrayModel,
-    DateTimeArrayModel, NestedIntegerArrayModel, OtherTypesArrayModel,
-    ArrayFieldSubclass,
+    ArrayFieldSubclass, CharArrayModel, DateTimeArrayModel, IntegerArrayModel,
+    NestedIntegerArrayModel, NullableIntegerArrayModel, OtherTypesArrayModel,
 )
 
 

tests/postgres_tests/test_ranges.py

@@ -2,16 +2,18 @@ import datetime
 import json
 import unittest
 
+from psycopg2.extras import DateRange, DateTimeTZRange, NumericRange
+
 from django import forms
-from django.contrib.postgres import forms as pg_forms, fields as pg_fields
-from django.contrib.postgres.validators import RangeMaxValueValidator, RangeMinValueValidator
+from django.contrib.postgres import fields as pg_fields, forms as pg_forms
+from django.contrib.postgres.validators import (
+    RangeMaxValueValidator, RangeMinValueValidator,
+)
 from django.core import exceptions, serializers
 from django.db import connection
 from django.test import TestCase
 from django.utils import timezone
 
-from psycopg2.extras import NumericRange, DateTimeTZRange, DateRange
-
 from .models import RangesModel