6 files changed, 45 insertions, 42 deletions
diff --git a/django/forms/fields.py b/django/forms/fields.py
index 59490a318a..cca2091ffa 100644
--- a/django/forms/fields.py
+++ b/django/forms/fields.py
@@ -16,20 +16,24 @@ from io import BytesIO
 
 from django.core import validators
 from django.core.exceptions import ValidationError
+# Provide this import for backwards compatibility.
+from django.core.validators import EMPTY_VALUES  # NOQA
 from django.forms.utils import from_current_timezone, to_current_timezone
 from django.forms.widgets import (
-    TextInput, NumberInput, EmailInput, URLInput, HiddenInput,
-    MultipleHiddenInput, ClearableFileInput, CheckboxInput, Select,
-    NullBooleanSelect, SelectMultiple, DateInput, DateTimeInput, TimeInput,
-    SplitDateTimeWidget, SplitHiddenDateTimeWidget, FILE_INPUT_CONTRADICTION
+    FILE_INPUT_CONTRADICTION, CheckboxInput, ClearableFileInput, DateInput,
+    DateTimeInput, EmailInput, HiddenInput, MultipleHiddenInput,
+    NullBooleanSelect, NumberInput, Select, SelectMultiple,
+    SplitDateTimeWidget, SplitHiddenDateTimeWidget, TextInput, TimeInput,
+    URLInput,
 )
-from django.utils import formats
-from django.utils.encoding import smart_text, force_str, force_text
-from django.utils.ipv6 import clean_ipv6_address
+from django.utils import formats, six
 from django.utils.dateparse import parse_duration
-from django.utils.deprecation import RemovedInDjango20Warning, RenameMethodsBase
+from django.utils.deprecation import (
+    RemovedInDjango20Warning, RenameMethodsBase,
+)
 from django.utils.duration import duration_string
-from django.utils import six
+from django.utils.encoding import force_str, force_text, smart_text
+from django.utils.ipv6 import clean_ipv6_address
 from django.utils.six.moves.urllib.parse import urlsplit, urlunsplit
 from django.utils.translation import ugettext_lazy as _, ungettext_lazy
 
diff --git a/django/forms/forms.py b/django/forms/forms.py
index c9b8cf2242..64405079d8 100644
--- a/django/forms/forms.py
+++ b/django/forms/forms.py
@@ -4,20 +4,21 @@ Form classes
 
 from __future__ import unicode_literals
 
-from collections import OrderedDict
 import copy
 import datetime
+from collections import OrderedDict
 
-from django.core.exceptions import ValidationError, NON_FIELD_ERRORS
+from django.core.exceptions import NON_FIELD_ERRORS, ValidationError
 from django.forms.fields import Field, FileField
-from django.forms.utils import flatatt, ErrorDict, ErrorList
-from django.forms.widgets import Media, MediaDefiningClass, TextInput, Textarea
-from django.utils.encoding import smart_text, force_text, python_2_unicode_compatible
+from django.forms.utils import ErrorDict, ErrorList, flatatt
+from django.forms.widgets import Media, MediaDefiningClass, Textarea, TextInput
+from django.utils import six
+from django.utils.encoding import (
+    force_text, python_2_unicode_compatible, smart_text,
+)
 from django.utils.html import conditional_escape, format_html
 from django.utils.safestring import mark_safe
 from django.utils.translation import ugettext as _
-from django.utils import six
-
 
 __all__ = ('BaseForm', 'Form')
 
diff --git a/django/forms/formsets.py b/django/forms/formsets.py
index 566269beb5..adacd00fdc 100644
--- a/django/forms/formsets.py
+++ b/django/forms/formsets.py
@@ -2,16 +2,15 @@ from __future__ import unicode_literals
 
 from django.core.exceptions import ValidationError
 from django.forms import Form
-from django.forms.fields import IntegerField, BooleanField
+from django.forms.fields import BooleanField, IntegerField
 from django.forms.utils import ErrorList
 from django.forms.widgets import HiddenInput
+from django.utils import six
 from django.utils.encoding import python_2_unicode_compatible
 from django.utils.functional import cached_property
 from django.utils.safestring import mark_safe
-from django.utils import six
 from django.utils.six.moves import range
-from django.utils.translation import ungettext, ugettext as _
-
+from django.utils.translation import ugettext as _, ungettext
 
 __all__ = ('BaseFormSet', 'formset_factory', 'all_valid')
 
diff --git a/django/forms/models.py b/django/forms/models.py
index 7d5473276c..c861eed321 100644
--- a/django/forms/models.py
+++ b/django/forms/models.py
@@ -9,18 +9,19 @@ from collections import OrderedDict
 from itertools import chain
 
 from django.core.exceptions import (
-    ImproperlyConfigured, ValidationError, NON_FIELD_ERRORS, FieldError)
-from django.forms.fields import Field, ChoiceField
-from django.forms.forms import DeclarativeFieldsMetaclass, BaseForm
+    NON_FIELD_ERRORS, FieldError, ImproperlyConfigured, ValidationError,
+)
+from django.forms.fields import ChoiceField, Field
+from django.forms.forms import BaseForm, DeclarativeFieldsMetaclass
 from django.forms.formsets import BaseFormSet, formset_factory
 from django.forms.utils import ErrorList
-from django.forms.widgets import (SelectMultiple, HiddenInput,
-    MultipleHiddenInput)
+from django.forms.widgets import (
+    HiddenInput, MultipleHiddenInput, SelectMultiple,
+)
 from django.utils import six
-from django.utils.encoding import smart_text, force_text
-from django.utils.text import get_text_list, capfirst
-from django.utils.translation import ugettext_lazy as _, ugettext
-
+from django.utils.encoding import force_text, smart_text
+from django.utils.text import capfirst, get_text_list
+from django.utils.translation import ugettext, ugettext_lazy as _
 
 __all__ = (
     'ModelForm', 'BaseModelForm', 'model_to_dict', 'fields_for_model',
diff --git a/django/forms/utils.py b/django/forms/utils.py
index 19c27f9b8c..ab0c80769b 100644
--- a/django/forms/utils.py
+++ b/django/forms/utils.py
@@ -3,21 +3,17 @@ from __future__ import unicode_literals
 import json
 import sys
 
-try:
-    from collections import UserList
-except ImportError:  # Python 2
-    from UserList import UserList
-
 from django.conf import settings
+from django.core.exceptions import ValidationError  # backwards compatibility
+from django.utils import six, timezone
 from django.utils.encoding import force_text, python_2_unicode_compatible
-from django.utils.html import format_html, format_html_join, escape
-from django.utils import timezone
+from django.utils.html import escape, format_html, format_html_join
 from django.utils.translation import ugettext_lazy as _
-from django.utils import six
 
-# Import ValidationError so that it can be imported from this
-# module to maintain backwards compatibility.
-from django.core.exceptions import ValidationError
+try:
+    from collections import UserList
+except ImportError:  # Python 2
+    from UserList import UserList
 
 
 def flatatt(attrs):
diff --git a/django/forms/widgets.py b/django/forms/widgets.py
index c434ecf0a1..fedd78c838 100644
--- a/django/forms/widgets.py
+++ b/django/forms/widgets.py
@@ -6,15 +6,17 @@ from __future__ import unicode_literals
 
 import copy
 import datetime
-from itertools import chain
 import re
+from itertools import chain
 
 from django.conf import settings
 from django.forms.utils import flatatt, to_current_timezone
 from django.utils import datetime_safe, formats, six
 from django.utils.datastructures import MultiValueDict
 from django.utils.dates import MONTHS
-from django.utils.encoding import force_str, force_text, python_2_unicode_compatible
+from django.utils.encoding import (
+    force_str, force_text, python_2_unicode_compatible,
+)
 from django.utils.formats import get_format
 from django.utils.html import conditional_escape, format_html
 from django.utils.safestring import mark_safe