[py3] Used six.with_metaclass wherever necessary.

django/contrib/admin/options.py

@@ -24,6 +24,7 @@ from django.utils.decorators import method_decorator
 from django.utils.datastructures import SortedDict
 from django.utils.html import escape, escapejs
 from django.utils.safestring import mark_safe
+from django.utils import six
 from django.utils.text import capfirst, get_text_list
 from django.utils.translation import ugettext as _
 from django.utils.translation import ungettext
@@ -57,9 +58,8 @@ FORMFIELD_FOR_DBFIELD_DEFAULTS = {
 
 csrf_protect_m = method_decorator(csrf_protect)
 
-class BaseModelAdmin(object):
+class BaseModelAdmin(six.with_metaclass(forms.MediaDefiningClass)):
     """Functionality common to both ModelAdmin and InlineAdmin."""
-    __metaclass__ = forms.MediaDefiningClass
 
     raw_id_fields = ()
     fields = None

django/db/models/base.py

@@ -24,6 +24,7 @@ from django.db.models.loading import register_models, get_model
 from django.utils.translation import ugettext_lazy as _
 from django.utils.functional import curry
 from django.utils.encoding import smart_str, force_unicode
+from django.utils import six
 from django.utils.text import get_text_list, capfirst
 
 
@@ -275,8 +276,8 @@ class ModelState(object):
         # This impacts validation only; it has no effect on the actual save.
         self.adding = True
 
-class Model(object):
-    __metaclass__ = ModelBase
+
+class ModelWithoutMeta(object):
     _deferred = False
 
     def __init__(self, *args, **kwargs):
@@ -369,7 +370,7 @@ class Model(object):
                     pass
             if kwargs:
                 raise TypeError("'%s' is an invalid keyword argument for this function" % kwargs.keys()[0])
-        super(Model, self).__init__()
+        super(ModelWithoutMeta, self).__init__()
         signals.post_init.send(sender=self.__class__, instance=self)
 
     def __repr__(self):
@@ -401,7 +402,7 @@ class Model(object):
         only module-level classes can be pickled by the default path.
         """
         if not self._deferred:
-            return super(Model, self).__reduce__()
+            return super(ModelWithoutMeta, self).__reduce__()
         data = self.__dict__
         defers = []
         for field in self._meta.fields:
@@ -876,6 +877,15 @@ class Model(object):
             raise ValidationError(errors)
 
 
+# For unknown reasons, six.with_metaclass doesn't work correctly for Model.
+# Fallback to exec'ing the appropriate syntax for each Python version.
+
+if six.PY3:
+    six.exec_("class Model(ModelWithoutMeta, metaclass=ModelBase): pass")
+else:
+    six.exec_("class Model(ModelWithoutMeta): __metaclass__ = ModelBase")
+
+
 ############################################
 # HELPER FUNCTIONS (CURRIED MODEL METHODS) #
 ############################################

django/forms/forms.py

@@ -14,6 +14,7 @@ from django.utils.datastructures import SortedDict
 from django.utils.html import conditional_escape, format_html
 from django.utils.encoding import StrAndUnicode, smart_unicode, force_unicode
 from django.utils.safestring import mark_safe
+from django.utils import six
 
 
 __all__ = ('BaseForm', 'Form')
@@ -380,14 +381,13 @@ class BaseForm(StrAndUnicode):
         """
         return [field for field in self if not field.is_hidden]
 
-class Form(BaseForm):
+class Form(six.with_metaclass(DeclarativeFieldsMetaclass, BaseForm)):
     "A collection of Fields, plus their associated data."
     # This is a separate class from BaseForm in order to abstract the way
     # self.fields is specified. This class (Form) is the one that does the
     # fancy metaclass stuff purely for the semantic sugar -- it allows one
     # to define a form using declarative syntax.
     # BaseForm itself has no way of designating self.fields.
-    __metaclass__ = DeclarativeFieldsMetaclass
 
 class BoundField(StrAndUnicode):
     "A Field plus data"

django/forms/models.py

@@ -15,6 +15,7 @@ from django.forms.widgets import (SelectMultiple, HiddenInput,
     MultipleHiddenInput, media_property)
 from django.utils.encoding import smart_unicode, force_unicode
 from django.utils.datastructures import SortedDict
+from django.utils import six
 from django.utils.text import get_text_list, capfirst
 from django.utils.translation import ugettext_lazy as _, ugettext
 
@@ -365,8 +366,8 @@ class BaseModelForm(BaseForm):
 
     save.alters_data = True
 
-class ModelForm(BaseModelForm):
-    __metaclass__ = ModelFormMetaclass
+class ModelForm(six.with_metaclass(ModelFormMetaclass, BaseModelForm)):
+    pass
 
 def modelform_factory(model, form=ModelForm, fields=None, exclude=None,
                       formfield_callback=None,  widgets=None):
@@ -401,6 +402,7 @@ def modelform_factory(model, form=ModelForm, fields=None, exclude=None,
 
     form_metaclass = ModelFormMetaclass
 
+    # TODO: this doesn't work under Python 3.
     if issubclass(form, BaseModelForm) and hasattr(form, '__metaclass__'):
         form_metaclass = form.__metaclass__
 

django/forms/widgets.py

@@ -17,6 +17,7 @@ from django.utils.translation import ugettext, ugettext_lazy
 from django.utils.encoding import StrAndUnicode, force_unicode
 from django.utils.safestring import mark_safe
 from django.utils import datetime_safe, formats
+from django.utils import six
 
 __all__ = (
     'Media', 'MediaDefiningClass', 'Widget', 'TextInput', 'PasswordInput',
@@ -153,8 +154,7 @@ class SubWidget(StrAndUnicode):
             args.append(self.choices)
         return self.parent_widget.render(*args)
 
-class Widget(object):
-    __metaclass__ = MediaDefiningClass
+class Widget(six.with_metaclass(MediaDefiningClass)):
     is_hidden = False          # Determines whether this corresponds to an <input type="hidden">.
     needs_multipart_form = False # Determines does this widget need multipart form
     is_localized = False