Fixed #20989 -- Removed useless explicit list comprehensions.

django/contrib/admin/filters.py

@@ -287,8 +287,8 @@ FieldListFilter.register(lambda f: bool(f.choices), ChoicesFieldListFilter)
 class DateFieldListFilter(FieldListFilter):
     def __init__(self, field, request, params, model, model_admin, field_path):
         self.field_generic = '%s__' % field_path
-        self.date_params = dict([(k, v) for k, v in params.items()
+        self.date_params = dict((k, v) for k, v in params.items()
-                                 if k.startswith(self.field_generic)])
+                                if k.startswith(self.field_generic))
 
         now = timezone.now()
         # When time zone support is enabled, convert "now" to the user's time

django/contrib/admin/helpers.py

@@ -112,7 +112,7 @@ class Fieldline(object):
                 yield AdminField(self.form, field, is_first=(i == 0))
 
     def errors(self):
-        return mark_safe('\n'.join([self.form[f].errors.as_ul() for f in self.fields if f not in self.readonly_fields]).strip('\n'))
+        return mark_safe('\n'.join(self.form[f].errors.as_ul() for f in self.fields if f not in self.readonly_fields).strip('\n'))
 
 class AdminField(object):
     def __init__(self, form, field, is_first):

django/contrib/admin/options.py

@@ -698,16 +698,16 @@ class ModelAdmin(BaseModelAdmin):
             # Avoid trying to iterate over None
             if not class_actions:
                 continue
-            actions.extend([self.get_action(action) for action in class_actions])
+            actions.extend(self.get_action(action) for action in class_actions)
 
         # get_action might have returned None, so filter any of those out.
         actions = filter(None, actions)
 
         # Convert the actions into an OrderedDict keyed by name.
-        actions = OrderedDict([
+        actions = OrderedDict(
             (name, (func, name, desc))
             for func, name, desc in actions
-        ])
+        )
 
         return actions
 

django/contrib/admin/widgets.py

@@ -119,7 +119,7 @@ def url_params_from_lookup_dict(lookups):
             if callable(v):
                 v = v()
             if isinstance(v, (tuple, list)):
-                v = ','.join([str(x) for x in v])
+                v = ','.join(str(x) for x in v)
             elif isinstance(v, bool):
                 # See django.db.fields.BooleanField.get_prep_lookup
                 v = ('0', '1')[v]
@@ -154,7 +154,7 @@ class ForeignKeyRawIdWidget(forms.TextInput):
 
             params = self.url_parameters()
             if params:
-                url = '?' + '&'.join(['%s=%s' % (k, v) for k, v in params.items()])
+                url = '?' + '&'.join('%s=%s' % (k, v) for k, v in params.items())
             else:
                 url = ''
             if "class" not in attrs:
@@ -199,7 +199,7 @@ class ManyToManyRawIdWidget(ForeignKeyRawIdWidget):
             # The related object is registered with the same AdminSite
             attrs['class'] = 'vManyToManyRawIdAdminField'
         if value:
-            value = ','.join([force_text(v) for v in value])
+            value = ','.join(force_text(v) for v in value)
         else:
             value = ''
         return super(ManyToManyRawIdWidget, self).render(name, value, attrs)

django/contrib/admindocs/utils.py

@@ -26,7 +26,7 @@ def trim_docstring(docstring):
         return ''
     # Convert tabs to spaces and split into lines
     lines = docstring.expandtabs().splitlines()
-    indent = min([len(line) - len(line.lstrip()) for line in lines if line.lstrip()])
+    indent = min(len(line) - len(line.lstrip()) for line in lines if line.lstrip())
     trimmed = [lines[0].lstrip()] + [line[indent:].rstrip() for line in lines[1:]]
     return "\n".join(trimmed).strip()
 

django/contrib/auth/backends.py

@@ -36,14 +36,14 @@ class ModelBackend(object):
                 user_groups_query = 'group__%s' % user_groups_field.related_query_name()
                 perms = Permission.objects.filter(**{user_groups_query: user_obj})
             perms = perms.values_list('content_type__app_label', 'codename').order_by()
-            user_obj._group_perm_cache = set(["%s.%s" % (ct, name) for ct, name in perms])
+            user_obj._group_perm_cache = set("%s.%s" % (ct, name) for ct, name in perms)
         return user_obj._group_perm_cache
 
     def get_all_permissions(self, user_obj, obj=None):
         if user_obj.is_anonymous() or obj is not None:
             return set()
         if not hasattr(user_obj, '_perm_cache'):
-            user_obj._perm_cache = set(["%s.%s" % (p.content_type.app_label, p.codename) for p in user_obj.user_permissions.select_related()])
+            user_obj._perm_cache = set("%s.%s" % (p.content_type.app_label, p.codename) for p in user_obj.user_permissions.select_related())
             user_obj._perm_cache.update(self.get_group_permissions(user_obj))
         return user_obj._perm_cache
 

django/contrib/auth/forms.py

@@ -330,10 +330,10 @@ class PasswordChangeForm(SetPasswordForm):
             )
         return old_password
 
-PasswordChangeForm.base_fields = OrderedDict([
+PasswordChangeForm.base_fields = OrderedDict(
     (k, PasswordChangeForm.base_fields[k])
     for k in ['old_password', 'new_password1', 'new_password2']
-])
+)
 
 
 class AdminPasswordChangeForm(forms.Form):

django/contrib/contenttypes/management.py

@@ -58,10 +58,10 @@ def update_contenttypes(app, created_models, verbosity=2, db=DEFAULT_DB_ALIAS, *
     # Confirm that the content type is stale before deletion.
     if to_remove:
         if kwargs.get('interactive', False):
-            content_type_display = '\n'.join([
+            content_type_display = '\n'.join(
                 '    %s | %s' % (ct.app_label, ct.model)
                 for ct in to_remove
-            ])
+            )
             ok_to_delete = input("""The following content types are stale and need to be deleted:
 
 %s

django/contrib/gis/db/models/sql/aggregates.py

@@ -32,7 +32,7 @@ class GeoAggregate(Aggregate):
         if hasattr(self.col, 'as_sql'):
             field_name, params = self.col.as_sql(qn, connection)
         elif isinstance(self.col, (list, tuple)):
-            field_name = '.'.join([qn(c) for c in self.col])
+            field_name = '.'.join(qn(c) for c in self.col)
         else:
             field_name = self.col
 

django/contrib/gis/feeds.py

@@ -15,7 +15,7 @@ class GeoFeedMixin(object):
         a single white space.  Given a tuple of coordinates, this will return
         a unicode GeoRSS representation.
         """
-        return ' '.join(['%f %f' % (coord[1], coord[0]) for coord in coords])
+        return ' '.join('%f %f' % (coord[1], coord[0]) for coord in coords)
 
     def add_georss_point(self, handler, coords, w3c_geo=False):
         """

django/contrib/gis/gdal/geometries.py

@@ -575,7 +575,7 @@ class LineString(OGRGeometry):
     @property
     def tuple(self):
         "Returns the tuple representation of this LineString."
-        return tuple([self[i] for i in xrange(len(self))])
+        return tuple(self[i] for i in xrange(len(self)))
     coords = tuple
 
     def _listarr(self, func):
@@ -632,14 +632,14 @@ class Polygon(OGRGeometry):
     @property
     def tuple(self):
         "Returns a tuple of LinearRing coordinate tuples."
-        return tuple([self[i].tuple for i in xrange(self.geom_count)])
+        return tuple(self[i].tuple for i in xrange(self.geom_count))
     coords = tuple
 
     @property
     def point_count(self):
         "The number of Points in this Polygon."
         # Summing up the number of points in each ring of the Polygon.
-        return sum([self[i].point_count for i in xrange(self.geom_count)])
+        return sum(self[i].point_count for i in xrange(self.geom_count))
 
     @property
     def centroid(self):
@@ -686,12 +686,12 @@ class GeometryCollection(OGRGeometry):
     def point_count(self):
         "The number of Points in this Geometry Collection."
         # Summing up the number of points in each geometry in this collection
-        return sum([self[i].point_count for i in xrange(self.geom_count)])
+        return sum(self[i].point_count for i in xrange(self.geom_count))
 
     @property
     def tuple(self):
         "Returns a tuple representation of this Geometry Collection."
-        return tuple([self[i].tuple for i in xrange(self.geom_count)])
+        return tuple(self[i].tuple for i in xrange(self.geom_count))
     coords = tuple
 
 # Multiple Geometry types.

django/contrib/gis/geos/collections.py

@@ -82,7 +82,7 @@ class GeometryCollection(GEOSGeometry):
     @property
     def kml(self):
         "Returns the KML for this Geometry Collection."
-        return '<MultiGeometry>%s</MultiGeometry>' % ''.join([g.kml for g in self])
+        return '<MultiGeometry>%s</MultiGeometry>' % ''.join(g.kml for g in self)
 
     @property
     def tuple(self):

django/contrib/gis/geos/coordseq.py

@@ -147,11 +147,11 @@ class GEOSCoordSeq(GEOSBase):
         if self.hasz: substr = '%s,%s,%s '
         else: substr = '%s,%s,0 '
         return '<coordinates>%s</coordinates>' % \
-            ''.join([substr % self[i] for i in xrange(len(self))]).strip()
+            ''.join(substr % self[i] for i in xrange(len(self))).strip()
 
     @property
     def tuple(self):
         "Returns a tuple version of this coordinate sequence."
         n = self.size
         if n == 1: return self[0]
-        else: return tuple([self[i] for i in xrange(n)])
+        else: return tuple(self[i] for i in xrange(n))

django/contrib/gis/geos/polygon.py

@@ -159,12 +159,12 @@ class Polygon(GEOSGeometry):
     @property
     def tuple(self):
         "Gets the tuple for each ring in this Polygon."
-        return tuple([self[i].tuple for i in xrange(len(self))])
+        return tuple(self[i].tuple for i in xrange(len(self)))
     coords = tuple
 
     @property
     def kml(self):
         "Returns the KML representation of this Polygon."
-        inner_kml = ''.join(["<innerBoundaryIs>%s</innerBoundaryIs>" % self[i+1].kml
+        inner_kml = ''.join("<innerBoundaryIs>%s</innerBoundaryIs>" % self[i+1].kml
-                             for i in xrange(self.num_interior_rings)])
+                             for i in xrange(self.num_interior_rings))
         return "<Polygon><outerBoundaryIs>%s</outerBoundaryIs>%s</Polygon>" % (self[0].kml, inner_kml)

django/contrib/gis/geos/tests/test_geos.py

@@ -838,9 +838,9 @@ class GEOSTest(unittest.TestCase, TestDataMixin):
         # Creating a GeometryCollection WKT string composed of other
         # collections and polygons.
         coll = [mp.wkt for mp in self.geometries.multipolygons if mp.valid]
-        coll.extend([mls.wkt for mls in self.geometries.multilinestrings])
+        coll.extend(mls.wkt for mls in self.geometries.multilinestrings)
-        coll.extend([p.wkt for p in self.geometries.polygons])
+        coll.extend(p.wkt for p in self.geometries.polygons)
-        coll.extend([mp.wkt for mp in self.geometries.multipoints])
+        coll.extend(mp.wkt for mp in self.geometries.multipoints)
         gc_wkt = 'GEOMETRYCOLLECTION(%s)' % ','.join(coll)
 
         # Should construct ok from WKT

django/contrib/gis/management/commands/ogrinspect.py

@@ -113,6 +113,6 @@ class Command(LabelCommand):
             rev_mapping = dict((v, k) for k, v in mapping_dict.items())
             output.extend(['', '# Auto-generated `LayerMapping` dictionary for %s model' % model_name,
                            '%s_mapping = {' % model_name.lower()])
-            output.extend(["    '%s' : '%s'," % (rev_mapping[ogr_fld], ogr_fld) for ogr_fld in ds[options['layer_key']].fields])
+            output.extend("    '%s' : '%s'," % (rev_mapping[ogr_fld], ogr_fld) for ogr_fld in ds[options['layer_key']].fields)
-            output.extend(["    '%s' : '%s'," % (options['geom_name'], mapping_dict[options['geom_name']]), '}'])
+            output.extend("    '%s' : '%s'," % (options['geom_name'], mapping_dict[options['geom_name']]), '}')
         return '\n'.join(output) + '\n'

django/contrib/gis/maps/google/gmap.py

@@ -150,7 +150,7 @@ class GoogleMap(object):
     @property
     def icons(self):
         "Returns a sequence of GIcon objects in this map."
-        return set([marker.icon for marker in self.markers if marker.icon])
+        return set(marker.icon for marker in self.markers if marker.icon)
 
 class GoogleMapSet(GoogleMap):
 

django/contrib/gis/maps/google/overlays.py

@@ -61,7 +61,7 @@ class GOverlayBase(object):
 
     def latlng_from_coords(self, coords):
         "Generates a JavaScript array of GLatLng objects for the given coordinates."
-        return '[%s]' % ','.join(['new GLatLng(%s,%s)' % (y, x) for x, y in coords])
+        return '[%s]' % ','.join('new GLatLng(%s,%s)' % (y, x) for x, y in coords)
 
     def add_event(self, event):
         "Attaches a GEvent to the overlay object."

django/contrib/gis/tests/geoadmin/tests.py

@@ -23,7 +23,7 @@ class GeoAdminTest(TestCase):
     def test_ensure_geographic_media(self):
         geoadmin = admin.site._registry[City]
         admin_js = geoadmin.media.render_js()
-        self.assertTrue(any([geoadmin.openlayers_url in js for js in admin_js]))
+        self.assertTrue(any(geoadmin.openlayers_url in js for js in admin_js))
 
     def test_olmap_OSM_rendering(self):
         geoadmin = admin.site._registry[City]

django/contrib/gis/tests/geoapp/test_feeds.py

@@ -28,7 +28,7 @@ class GeoFeedTest(TestCase):
 
     def assertChildNodes(self, elem, expected):
         "Taken from syndication/tests.py."
-        actual = set([n.nodeName for n in elem.childNodes])
+        actual = set(n.nodeName for n in elem.childNodes)
         expected = set(expected)
         self.assertEqual(actual, expected)
 

django/contrib/gis/tests/geoapp/test_sitemaps.py

@@ -32,7 +32,7 @@ class GeoSitemapTest(TestCase):
 
     def assertChildNodes(self, elem, expected):
         "Taken from syndication/tests.py."
-        actual = set([n.nodeName for n in elem.childNodes])
+        actual = set(n.nodeName for n in elem.childNodes)
         expected = set(expected)
         self.assertEqual(actual, expected)
 

django/contrib/gis/utils/wkt.py

@@ -30,10 +30,10 @@ def precision_wkt(geom, prec):
     coord_fmt = ' '.join([num_fmt, num_fmt])
 
     def formatted_coords(coords):
-        return ','.join([coord_fmt % c[:2] for c in coords])
+        return ','.join(coord_fmt % c[:2] for c in coords)
 
     def formatted_poly(poly):
-        return ','.join(['(%s)' % formatted_coords(r) for r in poly])
+        return ','.join('(%s)' % formatted_coords(r) for r in poly)
 
     def formatted_geom(g):
         gtype = str(g.geom_type).upper()
@@ -47,11 +47,11 @@ def precision_wkt(geom, prec):
         elif gtype == 'MULTIPOINT':
             yield formatted_coords(g.coords)
         elif gtype == 'MULTIPOLYGON':
-            yield ','.join(['(%s)' % formatted_poly(p) for p in g])
+            yield ','.join('(%s)' % formatted_poly(p) for p in g)
         elif gtype == 'GEOMETRYCOLLECTION':
-            yield ','.join([''.join([wkt for wkt in formatted_geom(child)]) for child in g])
+            yield ','.join(''.join(wkt for wkt in formatted_geom(child)) for child in g)
         else:
             raise TypeError
         yield ')'
 
-    return ''.join([wkt for wkt in formatted_geom(geom)])
+    return ''.join(wkt for wkt in formatted_geom(geom))

django/contrib/messages/storage/cookie.py

@@ -38,8 +38,8 @@ class MessageDecoder(json.JSONDecoder):
                 return Message(*obj[2:])
             return [self.process_messages(item) for item in obj]
         if isinstance(obj, dict):
-            return dict([(key, self.process_messages(value))
+            return dict((key, self.process_messages(value))
-                         for key, value in six.iteritems(obj)])
+                         for key, value in six.iteritems(obj))
         return obj
 
     def decode(self, s, **kwargs):

django/contrib/webdesign/lorem_ipsum.py

@@ -62,7 +62,7 @@ def paragraph():
 
     The paragraph consists of between 1 and 4 sentences, inclusive.
     """
-    return ' '.join([sentence() for i in range(random.randint(1, 4))])
+    return ' '.join(sentence() for i in range(random.randint(1, 4)))
 
 def paragraphs(count, common=True):
     """

django/core/cache/utils.py

@@ -10,6 +10,6 @@ TEMPLATE_FRAGMENT_KEY_TEMPLATE = 'template.cache.%s.%s'
 def make_template_fragment_key(fragment_name, vary_on=None):
     if vary_on is None:
         vary_on = ()
-    key = ':'.join([urlquote(var) for var in vary_on])
+    key = ':'.join(urlquote(var) for var in vary_on)
     args = hashlib.md5(force_bytes(key))
     return TEMPLATE_FRAGMENT_KEY_TEMPLATE % (fragment_name, args.hexdigest())

django/core/management/__init__.py

@@ -114,8 +114,8 @@ def get_commands():
         for app_name in apps:
             try:
                 path = find_management_module(app_name)
-                _commands.update(dict([(name, app_name)
+                _commands.update(dict((name, app_name)
-                                       for name in find_commands(path)]))
+                                       for name in find_commands(path)))
             except ImportError:
                 pass # No management module - ignore this app
 
@@ -336,7 +336,7 @@ class ManagementUtility(object):
             options = [opt for opt in options if opt[0] not in prev_opts]
 
             # filter options by current input
-            options = sorted([(k, v) for k, v in options if k.startswith(curr)])
+            options = sorted((k, v) for k, v in options if k.startswith(curr))
             for option in options:
                 opt_label = option[0]
                 # append '=' to options which require args

django/core/management/commands/migrate.py

@@ -164,7 +164,7 @@ class Command(BaseCommand):
             for app_name, model_list in all_models
         )
 
-        create_models = set([x for x in itertools.chain(*manifest.values())])
+        create_models = set(itertools.chain(*manifest.values()))
         emit_pre_migrate_signal(create_models, self.verbosity, self.interactive, connection.alias)
 
         # Create the tables for each model

django/core/management/sql.py

@@ -29,7 +29,7 @@ def sql_create(app, style, connection):
     app_models = models.get_models(app, include_auto_created=True)
     final_output = []
     tables = connection.introspection.table_names()
-    known_models = set([model for model in connection.introspection.installed_models(tables) if model not in app_models])
+    known_models = set(model for model in connection.introspection.installed_models(tables) if model not in app_models)
     pending_references = {}
 
     for model in app_models:

django/core/management/utils.py

@@ -52,7 +52,7 @@ def handle_extensions(extensions=('html',), ignored=('py',)):
     for i, ext in enumerate(ext_list):
         if not ext.startswith('.'):
             ext_list[i] = '.%s' % ext_list[i]
-    return set([x for x in ext_list if x.strip('.') not in ignored])
+    return set(x for x in ext_list if x.strip('.') not in ignored)
 
 def find_command(cmd, path=None, pathext=None):
     if path is None:

django/core/management/validation.py

@@ -161,7 +161,7 @@ def get_validation_errors(outfile, app=None):
                         for rel_field in f.foreign_related_fields:
                             has_unique_field = has_unique_field or rel_field.unique
                         if not has_unique_field:
-                            e.add(opts, "Field combination '%s' under model '%s' must have a unique=True constraint" % (','.join([rel_field.name for rel_field in f.foreign_related_fields]), f.rel.to.__name__))
+                            e.add(opts, "Field combination '%s' under model '%s' must have a unique=True constraint" % (','.join(rel_field.name for rel_field in f.foreign_related_fields), f.rel.to.__name__))
                     else:
                         if not f.foreign_related_fields[0].unique:
                             e.add(opts, "Field '%s' under model '%s' must have a unique=True constraint." % (f.foreign_related_fields[0].name, f.rel.to.__name__))

django/core/urlresolvers.py

@@ -62,7 +62,7 @@ class ResolverMatch(object):
 
     @property
     def view_name(self):
-        return ':'.join([ x for x in [ self.namespace, self.url_name ]  if x ])
+        return ':'.join(filter(bool, (self.namespace, self.url_name)))
 
     def __getitem__(self, index):
         return (self.func, self.args, self.kwargs)[index]
@@ -274,7 +274,7 @@ class RegexURLResolver(LocaleRegexProvider):
                         for matches, pat, defaults in pattern.reverse_dict.getlist(name):
                             new_matches = []
                             for piece, p_args in parent:
-                                new_matches.extend([(piece + suffix, p_args + args) for (suffix, args) in matches])
+                                new_matches.extend((piece + suffix, p_args + args) for (suffix, args) in matches)
                             lookups.appendlist(name, (new_matches, p_pattern + pat, dict(defaults, **pattern.default_kwargs)))
                     for namespace, (prefix, sub_pattern) in pattern.namespace_dict.items():
                         namespaces[namespace] = (p_pattern + prefix, sub_pattern)
@@ -321,7 +321,7 @@ class RegexURLResolver(LocaleRegexProvider):
                 except Resolver404 as e:
                     sub_tried = e.args[0].get('tried')
                     if sub_tried is not None:
-                        tried.extend([[pattern] + t for t in sub_tried])
+                        tried.extend([pattern] + t for t in sub_tried)
                     else:
                         tried.append([pattern])
                 else:

django/db/backends/__init__.py

@@ -1255,7 +1255,7 @@ class BaseDatabaseIntrospection(object):
                 if not router.allow_migrate(self.connection.alias, model):
                     continue
                 tables.add(model._meta.db_table)
-                tables.update([f.m2m_db_table() for f in model._meta.local_many_to_many])
+                tables.update(f.m2m_db_table() for f in model._meta.local_many_to_many)
         tables = list(tables)
         if only_existing:
             existing_tables = self.table_names()

django/db/backends/mysql/compiler.py

@@ -20,7 +20,7 @@ class SQLCompiler(compiler.SQLCompiler):
     def as_subquery_condition(self, alias, columns, qn):
         qn2 = self.connection.ops.quote_name
         sql, params = self.as_sql()
-        return '(%s) IN (%s)' % (', '.join(['%s.%s' % (qn(alias), qn2(column)) for column in columns]), sql), params
+        return '(%s) IN (%s)' % (', '.join('%s.%s' % (qn(alias), qn2(column)) for column in columns), sql), params
 
 
 class SQLInsertCompiler(compiler.SQLInsertCompiler, SQLCompiler):

django/db/backends/mysql/introspection.py

@@ -54,7 +54,7 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
             SELECT column_name, numeric_precision, numeric_scale FROM information_schema.columns
             WHERE table_name = %s AND table_schema = DATABASE()
                 AND data_type='decimal'""", [table_name])
-        numeric_map = dict([(line[0], tuple([int(n) for n in line[1:]])) for line in cursor.fetchall()])
+        numeric_map = dict((line[0], tuple(int(n) for n in line[1:])) for line in cursor.fetchall())
 
         cursor.execute("SELECT * FROM %s LIMIT 1" % self.connection.ops.quote_name(table_name))
         return [FieldInfo(*((force_text(line[0]),)
@@ -69,7 +69,7 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
         Returns a dictionary of {field_name: field_index} for the given table.
         Indexes are 0-based.
         """
-        return dict([(d[0], i) for i, d in enumerate(self.get_table_description(cursor, table_name))])
+        return dict((d[0], i) for i, d in enumerate(self.get_table_description(cursor, table_name)))
 
     def get_relations(self, cursor, table_name):
         """

django/db/backends/oracle/base.py

@@ -860,12 +860,12 @@ class FormatStylePlaceholderCursor(object):
     def fetchmany(self, size=None):
         if size is None:
             size = self.arraysize
-        return tuple([_rowfactory(r, self.cursor)
+        return tuple(_rowfactory(r, self.cursor)
-                      for r in self.cursor.fetchmany(size)])
+                      for r in self.cursor.fetchmany(size))
 
     def fetchall(self):
-        return tuple([_rowfactory(r, self.cursor)
+        return tuple(_rowfactory(r, self.cursor)
-                      for r in self.cursor.fetchall()])
+                      for r in self.cursor.fetchall())
 
     def var(self, *args):
         return VariableWrapper(self.cursor.var(*args))

django/db/backends/oracle/introspection.py

@@ -66,7 +66,7 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
         Returns a dictionary of {field_name: field_index} for the given table.
         Indexes are 0-based.
         """
-        return dict([(d[0], i) for i, d in enumerate(self.get_table_description(cursor, table_name))])
+        return dict((d[0], i) for i, d in enumerate(self.get_table_description(cursor, table_name)))
 
     def get_relations(self, cursor, table_name):
         """

django/db/backends/sqlite3/schema.py

@@ -57,8 +57,8 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
         field_maps = list(mapping.items())
         self.execute("INSERT INTO %s (%s) SELECT %s FROM %s;" % (
             self.quote_name(temp_model._meta.db_table),
-            ', '.join([x for x, y in field_maps]),
+            ', '.join(x for x, y in field_maps),
-            ', '.join([y for x, y in field_maps]),
+            ', '.join(y for x, y in field_maps),
             self.quote_name(model._meta.db_table),
         ))
         # Delete the old table

django/db/migrations/autodetector.py

@@ -145,8 +145,8 @@ class MigrationAutodetector(object):
             old_model_state = self.from_state.models[app_label, model_name]
             new_model_state = self.to_state.models[app_label, model_name]
             # New fields
-            old_field_names = set([x for x, y in old_model_state.fields])
+            old_field_names = set(x for x, y in old_model_state.fields)
-            new_field_names = set([x for x, y in new_model_state.fields])
+            new_field_names = set(x for x, y in new_model_state.fields)
             for field_name in new_field_names - old_field_names:
                 field = new_model_state.get_field_by_name(field_name)
                 # Scan to see if this is actually a rename!

django/db/migrations/writer.py

@@ -104,7 +104,7 @@ class MigrationWriter(object):
                 imports.update(k_imports)
                 imports.update(v_imports)
                 strings.append((k_string, v_string))
-            return "{%s}" % (", ".join(["%s: %s" % (k, v) for k, v in strings])), imports
+            return "{%s}" % (", ".join("%s: %s" % (k, v) for k, v in strings)), imports
         # Datetimes
         elif isinstance(value, (datetime.datetime, datetime.date)):
             return repr(value), set(["import datetime"])

django/db/models/base.py

@@ -159,7 +159,7 @@ class ModelBase(type):
         new_fields = new_class._meta.local_fields + \
                      new_class._meta.local_many_to_many + \
                      new_class._meta.virtual_fields
-        field_names = set([f.name for f in new_fields])
+        field_names = set(f.name for f in new_fields)
 
         # Basic setup for proxy models.
         if is_proxy:
@@ -321,7 +321,7 @@ class ModelBase(type):
 
         # Give the class a docstring -- its definition.
         if cls.__doc__ is None:
-            cls.__doc__ = "%s(%s)" % (cls.__name__, ", ".join([f.attname for f in opts.fields]))
+            cls.__doc__ = "%s(%s)" % (cls.__name__, ", ".join(f.attname for f in opts.fields))
 
         if hasattr(cls, 'get_absolute_url'):
             cls.get_absolute_url = update_wrapper(curry(get_absolute_url, opts, cls.get_absolute_url),

django/db/models/deletion.py

@@ -234,8 +234,8 @@ class Collector(object):
                     found = True
             if not found:
                 return
-        self.data = OrderedDict([(model, self.data[model])
+        self.data = OrderedDict((model, self.data[model])
-                                for model in sorted_models])
+                                for model in sorted_models)
 
     def delete(self):
         # sort instance collections

django/db/models/options.py

@@ -320,7 +320,7 @@ class Options(object):
                     cache.append((field, model))
                 else:
                     cache.append((field, parent))
-        cache.extend([(f, None) for f in self.local_fields])
+        cache.extend((f, None) for f in self.local_fields)
         self._field_cache = tuple(cache)
         self._field_name_cache = [x for x, _ in cache]
 

django/db/models/query.py

@@ -1206,7 +1206,7 @@ class ValuesListQuerySet(ValuesQuerySet):
 
             for row in self.query.get_compiler(self.db).results_iter():
                 data = dict(zip(names, row))
-                yield tuple([data[f] for f in fields])
+                yield tuple(data[f] for f in fields)
 
     def _clone(self, *args, **kwargs):
         clone = super(ValuesListQuerySet, self)._clone(*args, **kwargs)

django/db/models/sql/aggregates.py

@@ -77,7 +77,7 @@ class Aggregate(object):
         if hasattr(self.col, 'as_sql'):
             field_name, params = self.col.as_sql(qn, connection)
         elif isinstance(self.col, (list, tuple)):
-            field_name = '.'.join([qn(c) for c in self.col])
+            field_name = '.'.join(qn(c) for c in self.col)
         else:
             field_name = self.col
 

django/db/models/sql/compiler.py

@@ -718,11 +718,11 @@ class SQLCompiler(object):
                     loaded_fields = self.query.get_loaded_field_names().get(self.query.model, set()) or self.query.select
                     aggregate_start = len(self.query.extra_select) + len(loaded_fields)
                     aggregate_end = aggregate_start + len(self.query.aggregate_select)
-                    row = tuple(row[:aggregate_start]) + tuple([
+                    row = tuple(row[:aggregate_start]) + tuple(
                         self.query.resolve_aggregate(value, aggregate, self.connection)
                         for (alias, aggregate), value
                         in zip(self.query.aggregate_select.items(), row[aggregate_start:aggregate_end])
-                    ]) + tuple(row[aggregate_end:])
+                    ) + tuple(row[aggregate_end:])
 
                 yield row
 
@@ -827,7 +827,7 @@ class SQLInsertCompiler(SQLCompiler):
 
         has_fields = bool(self.query.fields)
         fields = self.query.fields if has_fields else [opts.pk]
-        result.append('(%s)' % ', '.join([qn(f.column) for f in fields]))
+        result.append('(%s)' % ', '.join(qn(f.column) for f in fields))
 
         if has_fields:
             params = values = [
@@ -1007,7 +1007,7 @@ class SQLUpdateCompiler(SQLCompiler):
             # selecting from the updating table (e.g. MySQL).
             idents = []
             for rows in query.get_compiler(self.using).execute_sql(MULTI):
-                idents.extend([r[0] for r in rows])
+                idents.extend(r[0] for r in rows)
             self.query.add_filter(('pk__in', idents))
             self.query.related_ids = idents
         else:

django/db/models/sql/query.py

@@ -371,11 +371,11 @@ class Query(object):
         if result is None:
             result = [None for q in query.aggregate_select.items()]
 
-        return dict([
+        return dict(
             (alias, self.resolve_aggregate(val, aggregate, connection=connections[using]))
             for (alias, aggregate), val
             in zip(query.aggregate_select.items(), result)
-        ])
+        )
 
     def get_count(self, using):
         """
@@ -1755,7 +1755,7 @@ class Query(object):
         """
         Callback used by get_deferred_field_names().
         """
-        target[model] = set([f.name for f in fields])
+        target[model] = set(f.name for f in fields)
 
     def set_aggregate_mask(self, names):
         "Set the mask of aggregates that will actually be returned by the SELECT"
@@ -1790,10 +1790,10 @@ class Query(object):
         if self._aggregate_select_cache is not None:
             return self._aggregate_select_cache
         elif self.aggregate_select_mask is not None:
-            self._aggregate_select_cache = OrderedDict([
+            self._aggregate_select_cache = OrderedDict(
                 (k, v) for k, v in self.aggregates.items()
                 if k in self.aggregate_select_mask
-            ])
+            )
             return self._aggregate_select_cache
         else:
             return self.aggregates
@@ -1803,10 +1803,10 @@ class Query(object):
         if self._extra_select_cache is not None:
             return self._extra_select_cache
         elif self.extra_select_mask is not None:
-            self._extra_select_cache = OrderedDict([
+            self._extra_select_cache = OrderedDict(
                 (k, v) for k, v in self.extra.items()
                 if k in self.extra_select_mask
-            ])
+            )
             return self._extra_select_cache
         else:
             return self.extra

django/forms/fields.py

@@ -874,8 +874,8 @@ class MultipleChoiceField(ChoiceField):
             data = []
         if len(initial) != len(data):
             return True
-        initial_set = set([force_text(value) for value in initial])
+        initial_set = set(force_text(value) for value in initial)
-        data_set = set([force_text(value) for value in data])
+        data_set = set(force_text(value) for value in data)
         return data_set != initial_set
 
 

django/forms/formsets.py

@@ -380,17 +380,17 @@ class BaseFormSet(object):
         # XXX: there is no semantic division between forms here, there
         # probably should be. It might make sense to render each form as a
         # table row with each field as a td.
-        forms = ' '.join([form.as_table() for form in self])
+        forms = ' '.join(form.as_table() for form in self)
         return mark_safe('\n'.join([six.text_type(self.management_form), forms]))
 
     def as_p(self):
         "Returns this formset rendered as HTML <p>s."
-        forms = ' '.join([form.as_p() for form in self])
+        forms = ' '.join(form.as_p() for form in self)
         return mark_safe('\n'.join([six.text_type(self.management_form), forms]))
 
     def as_ul(self):
         "Returns this formset rendered as HTML <li>s."
-        forms = ' '.join([form.as_ul() for form in self])
+        forms = ' '.join(form.as_ul() for form in self)
         return mark_safe('\n'.join([six.text_type(self.management_form), forms]))
 
 def formset_factory(form, formset=BaseFormSet, extra=1, can_order=False,

django/forms/models.py

@@ -1181,7 +1181,7 @@ class ModelMultipleChoiceField(ModelChoiceField):
                     params={'pk': pk},
                 )
         qs = self.queryset.filter(**{'%s__in' % key: value})
-        pks = set([force_text(getattr(o, key)) for o in qs])
+        pks = set(force_text(getattr(o, key)) for o in qs)
         for val in value:
             if force_text(val) not in pks:
                 raise ValidationError(
@@ -1208,8 +1208,8 @@ class ModelMultipleChoiceField(ModelChoiceField):
             data = []
         if len(initial) != len(data):
             return True
-        initial_set = set([force_text(value) for value in self.prepare_value(initial)])
+        initial_set = set(force_text(value) for value in self.prepare_value(initial))
-        data_set = set([force_text(value) for value in data])
+        data_set = set(force_text(value) for value in data)
         return data_set != initial_set
 
 

django/forms/util.py

@@ -49,7 +49,7 @@ class ErrorDict(dict):
                            ))
 
     def as_text(self):
-        return '\n'.join(['* %s\n%s' % (k, '\n'.join(['  * %s' % force_text(i) for i in v])) for k, v in self.items()])
+        return '\n'.join('* %s\n%s' % (k, '\n'.join('  * %s' % force_text(i) for i in v)) for k, v in self.items())
 
 @python_2_unicode_compatible
 class ErrorList(list):
@@ -69,7 +69,7 @@ class ErrorList(list):
 
     def as_text(self):
         if not self: return ''
-        return '\n'.join(['* %s' % force_text(e) for e in self])
+        return '\n'.join('* %s' % force_text(e) for e in self)
 
     def __repr__(self):
         return repr([force_text(e) for e in self])

django/template/base.py

@@ -88,8 +88,8 @@ class VariableDoesNotExist(Exception):
         self.params = params
 
     def __str__(self):
-        return self.msg % tuple([force_text(p, errors='replace')
+        return self.msg % tuple(force_text(p, errors='replace')
-                                 for p in self.params])
+                                 for p in self.params)
 
 class InvalidTemplateLibrary(Exception):
     pass
@@ -1012,7 +1012,7 @@ def parse_bits(parser, bits, params, varargs, varkw, defaults,
         # Some positional arguments were not supplied
         raise TemplateSyntaxError(
             "'%s' did not receive value(s) for the argument(s): %s" %
-            (name, ", ".join(["'%s'" % p for p in unhandled_params])))
+            (name, ", ".join("'%s'" % p for p in unhandled_params)))
     return args, kwargs
 
 def generic_tag_compiler(parser, token, params, varargs, varkw, defaults,

django/template/defaulttags.py

@@ -205,7 +205,7 @@ class ForNode(Node):
                     # don't want to leave any vars from the previous loop on the
                     # context.
                     context.pop()
-        return mark_safe(''.join([force_text(n) for n in nodelist]))
+        return mark_safe(''.join(force_text(n) for n in nodelist))
 
 class IfChangedNode(Node):
     child_nodelists = ('nodelist_true', 'nodelist_false')
@@ -410,8 +410,8 @@ class URLNode(Node):
     def render(self, context):
         from django.core.urlresolvers import reverse, NoReverseMatch
         args = [arg.resolve(context) for arg in self.args]
-        kwargs = dict([(smart_text(k, 'ascii'), v.resolve(context))
+        kwargs = dict((smart_text(k, 'ascii'), v.resolve(context))
-                       for k, v in self.kwargs.items()])
+                       for k, v in self.kwargs.items())
 
         view_name = self.view_name.resolve(context)
 
@@ -502,8 +502,8 @@ class WithNode(Node):
         return "<WithNode>"
 
     def render(self, context):
-        values = dict([(key, val.resolve(context)) for key, val in
+        values = dict((key, val.resolve(context)) for key, val in
-                       six.iteritems(self.extra_context)])
+                       six.iteritems(self.extra_context))
         with context.push(**values):
             return self.nodelist.render(context)
 

django/template/loader_tags.py

@@ -112,8 +112,8 @@ class ExtendsNode(Node):
             # The ExtendsNode has to be the first non-text node.
             if not isinstance(node, TextNode):
                 if not isinstance(node, ExtendsNode):
-                    blocks = dict([(n.name, n) for n in
+                    blocks = dict((n.name, n) for n in
-                                   compiled_parent.nodelist.get_nodes_by_type(BlockNode)])
+                                   compiled_parent.nodelist.get_nodes_by_type(BlockNode))
                     block_context.add_blocks(blocks)
                 break
 

django/test/_doctest.py

@@ -598,7 +598,7 @@ class DocTestParser:
         # If all lines begin with the same indentation, then strip it.
         min_indent = self._min_indent(string)
         if min_indent > 0:
-            string = '\n'.join([l[min_indent:] for l in string.split('\n')])
+            string = '\n'.join(l[min_indent:] for l in string.split('\n'))
 
         output = []
         charno, lineno = 0, 0
@@ -670,7 +670,7 @@ class DocTestParser:
         source_lines = m.group('source').split('\n')
         self._check_prompt_blank(source_lines, indent, name, lineno)
         self._check_prefix(source_lines[1:], ' '*indent + '.', name, lineno)
-        source = '\n'.join([sl[indent+4:] for sl in source_lines])
+        source = '\n'.join(sl[indent+4:] for sl in source_lines)
 
         # Divide want into lines; check that it's properly indented; and
         # then strip the indentation.  Spaces before the last newline should
@@ -681,7 +681,7 @@ class DocTestParser:
             del want_lines[-1]  # forget final newline & spaces after it
         self._check_prefix(want_lines, ' '*indent, name,
                            lineno + len(source_lines))
-        want = '\n'.join([wl[indent:] for wl in want_lines])
+        want = '\n'.join(wl[indent:] for wl in want_lines)
 
         # If `want` contains a traceback message, then extract it.
         m = self._EXCEPTION_RE.match(want)

django/utils/cache.py

@@ -76,7 +76,7 @@ def patch_cache_control(response, **kwargs):
 
     for (k, v) in kwargs.items():
         cc[k.replace('_', '-')] = v
-    cc = ', '.join([dictvalue(el) for el in cc.items()])
+    cc = ', '.join(dictvalue(el) for el in cc.items())
     response['Cache-Control'] = cc
 
 def get_max_age(response):
@@ -86,8 +86,8 @@ def get_max_age(response):
     """
     if not response.has_header('Cache-Control'):
         return
-    cc = dict([_to_tuple(el) for el in
+    cc = dict(_to_tuple(el) for el in
-        cc_delim_re.split(response['Cache-Control'])])
+        cc_delim_re.split(response['Cache-Control']))
     if 'max-age' in cc:
         try:
             return int(cc['max-age'])
@@ -144,7 +144,7 @@ def patch_vary_headers(response, newheaders):
     else:
         vary_headers = []
     # Use .lower() here so we treat headers as case-insensitive.
-    existing_headers = set([header.lower() for header in vary_headers])
+    existing_headers = set(header.lower() for header in vary_headers)
     additional_headers = [newheader for newheader in newheaders
                           if newheader.lower() not in existing_headers]
     response['Vary'] = ', '.join(vary_headers + additional_headers)
@@ -156,7 +156,7 @@ def has_vary_header(response, header_query):
     if not response.has_header('Vary'):
         return False
     vary_headers = cc_delim_re.split(response['Vary'])
-    existing_headers = set([header.lower() for header in vary_headers])
+    existing_headers = set(header.lower() for header in vary_headers)
     return header_query.lower() in existing_headers
 
 def _i18n_cache_key_suffix(request, cache_key):

django/utils/checksums.py

@@ -17,8 +17,8 @@ def luhn(candidate):
     if not isinstance(candidate, six.string_types):
         candidate = str(candidate)
     try:
-        evens = sum([int(c) for c in candidate[-1::-2]])
+        evens = sum(int(c) for c in candidate[-1::-2])
-        odds = sum([LUHN_ODD_LOOKUP[int(c)] for c in candidate[-2::-2]])
+        odds = sum(LUHN_ODD_LOOKUP[int(c)] for c in candidate[-2::-2])
         return ((evens + odds) % 10 == 0)
     except ValueError:  # Raised if an int conversion fails
         return False

django/utils/crypto.py

@@ -73,7 +73,7 @@ def get_random_string(length=12,
                     time.time(),
                     settings.SECRET_KEY)).encode('utf-8')
                 ).digest())
-    return ''.join([random.choice(allowed_chars) for i in range(length)])
+    return ''.join(random.choice(allowed_chars) for i in range(length))
 
 
 def constant_time_compare(val1, val2):

django/utils/datastructures.py

@@ -231,7 +231,7 @@ class SortedDict(dict):
         Replaces the normal dict.__repr__ with a version that returns the keys
         in their sorted order.
         """
-        return '{%s}' % ', '.join(['%r: %r' % (k, v) for k, v in six.iteritems(self)])
+        return '{%s}' % ', '.join('%r: %r' % (k, v) for k, v in six.iteritems(self))
 
     def clear(self):
         super(SortedDict, self).clear()

django/utils/html.py

@@ -32,7 +32,7 @@ simple_url_2_re = re.compile(r'^www\.|^(?!http)\w[^@]+\.(com|edu|gov|int|mil|net
 simple_email_re = re.compile(r'^\S+@\S+\.\S+$')
 link_target_attribute_re = re.compile(r'(<a [^>]*?)target=[^\s>]+')
 html_gunk_re = re.compile(r'(?:<br clear="all">|<i><\/i>|<b><\/b>|<em><\/em>|<strong><\/strong>|<\/?smallcaps>|<\/?uppercase>)', re.IGNORECASE)
-hard_coded_bullets_re = re.compile(r'((?:<p>(?:%s).*?[a-zA-Z].*?</p>\s*)+)' % '|'.join([re.escape(x) for x in DOTS]), re.DOTALL)
+hard_coded_bullets_re = re.compile(r'((?:<p>(?:%s).*?[a-zA-Z].*?</p>\s*)+)' % '|'.join(re.escape(x) for x in DOTS), re.DOTALL)
 trailing_empty_content_re = re.compile(r'(?:<p>(?:&nbsp;|\s|<br \/>)*?</p>\s*)+\Z')
 
 
@@ -81,8 +81,8 @@ def format_html(format_string, *args, **kwargs):
     of str.format or % interpolation to build up small HTML fragments.
     """
     args_safe = map(conditional_escape, args)
-    kwargs_safe = dict([(k, conditional_escape(v)) for (k, v) in
+    kwargs_safe = dict((k, conditional_escape(v)) for (k, v) in
-                        six.iteritems(kwargs)])
+                        six.iteritems(kwargs))
     return mark_safe(format_string.format(*args_safe, **kwargs_safe))
 
 def format_html_join(sep, format_string, args_generator):

django/utils/termcolors.py

@@ -5,8 +5,8 @@ termcolors.py
 from django.utils import six
 
 color_names = ('black', 'red', 'green', 'yellow', 'blue', 'magenta', 'cyan', 'white')
-foreground = dict([(color_names[x], '3%s' % x) for x in range(8)])
+foreground = dict((color_names[x], '3%s' % x) for x in range(8))
-background = dict([(color_names[x], '4%s' % x) for x in range(8)])
+background = dict((color_names[x], '4%s' % x) for x in range(8))
 
 RESET = '0'
 opt_dict = {'bold': '1', 'underscore': '4', 'blink': '5', 'reverse': '7', 'conceal': '8'}

django/utils/text.py

@@ -238,7 +238,7 @@ def get_text_list(list_, last_word=ugettext_lazy('or')):
     if len(list_) == 1: return force_text(list_[0])
     return '%s %s %s' % (
         # Translators: This string is used as a separator between list elements
-        _(', ').join([force_text(i) for i in list_][:-1]),
+        _(', ').join(force_text(i) for i in list_[:-1]),
         force_text(last_word), force_text(list_[-1]))
 get_text_list = allow_lazy(get_text_list, six.text_type)
 

django/utils/translation/__init__.py

@@ -179,7 +179,7 @@ def _string_concat(*strings):
     Lazy variant of string concatenation, needed for translations that are
     constructed from multiple parts.
     """
-    return ''.join([force_text(s) for s in strings])
+    return ''.join(force_text(s) for s in strings)
 string_concat = lazy(_string_concat, six.text_type)
 
 def get_language_info(lang_code):

tests/backends/tests.py

@@ -79,7 +79,7 @@ class OracleChecks(unittest.TestCase):
         # than 4000 chars and read it properly
         c = connection.cursor()
         c.execute('CREATE TABLE ltext ("TEXT" NCLOB)')
-        long_str = ''.join([six.text_type(x) for x in xrange(4000)])
+        long_str = ''.join(six.text_type(x) for x in xrange(4000))
         c.execute('INSERT INTO ltext VALUES (%s)', [long_str])
         c.execute('SELECT text FROM ltext')
         row = c.fetchone()

tests/file_uploads/views.py

@@ -89,14 +89,14 @@ def file_upload_echo(request):
     """
     Simple view to echo back info about uploaded files for tests.
     """
-    r = dict([(k, f.name) for k, f in request.FILES.items()])
+    r = dict((k, f.name) for k, f in request.FILES.items())
     return HttpResponse(json.dumps(r))
 
 def file_upload_echo_content(request):
     """
     Simple view to echo back the content of uploaded files for tests.
     """
-    r = dict([(k, f.read().decode('utf-8')) for k, f in request.FILES.items()])
+    r = dict((k, f.read().decode('utf-8')) for k, f in request.FILES.items())
     return HttpResponse(json.dumps(r))
 
 def file_upload_quota(request):

tests/forms_tests/tests/test_error_messages.py

@@ -221,7 +221,7 @@ class FormsErrorMessagesTestCase(TestCase, AssertFormErrorsMixin):
 
             def as_divs(self):
                 if not self: return ''
-                return mark_safe('<div class="error">%s</div>' % ''.join(['<p>%s</p>' % e for e in self]))
+                return mark_safe('<div class="error">%s</div>' % ''.join('<p>%s</p>' % e for e in self))
 
         # This form should print errors the default way.
         form1 = TestForm({'first_name': 'John'})

tests/forms_tests/tests/test_extra.py

@@ -723,7 +723,7 @@ class FormsExtraTestCase(TestCase, AssertFormErrorsMixin):
 
             def as_divs(self):
                 if not self: return ''
-                return '<div class="errorlist">%s</div>' % ''.join(['<div class="error">%s</div>' % force_text(e) for e in self])
+                return '<div class="errorlist">%s</div>' % ''.join('<div class="error">%s</div>' % force_text(e) for e in self)
 
         class CommentForm(Form):
             name = CharField(max_length=50, required=False)

tests/forms_tests/tests/test_forms.py

@@ -437,11 +437,11 @@ class FormsTestCase(TestCase):
             name = ChoiceField(choices=[('john', 'John'), ('paul', 'Paul'), ('george', 'George'), ('ringo', 'Ringo')], widget=RadioSelect)
 
         f = BeatleForm(auto_id=False)
-        self.assertHTMLEqual('\n'.join([str(bf) for bf in f['name']]), """<label><input type="radio" name="name" value="john" /> John</label>
+        self.assertHTMLEqual('\n'.join(str(bf) for bf in f['name']), """<label><input type="radio" name="name" value="john" /> John</label>
 <label><input type="radio" name="name" value="paul" /> Paul</label>
 <label><input type="radio" name="name" value="george" /> George</label>
 <label><input type="radio" name="name" value="ringo" /> Ringo</label>""")
-        self.assertHTMLEqual('\n'.join(['<div>%s</div>' % bf for bf in f['name']]), """<div><label><input type="radio" name="name" value="john" /> John</label></div>
+        self.assertHTMLEqual('\n'.join('<div>%s</div>' % bf for bf in f['name']), """<div><label><input type="radio" name="name" value="john" /> John</label></div>
 <div><label><input type="radio" name="name" value="paul" /> Paul</label></div>
 <div><label><input type="radio" name="name" value="george" /> George</label></div>
 <div><label><input type="radio" name="name" value="ringo" /> Ringo</label></div>""")
@@ -452,7 +452,7 @@ class FormsTestCase(TestCase):
             name = CharField()
 
         f = BeatleForm(auto_id=False)
-        self.assertHTMLEqual('\n'.join([str(bf) for bf in f['name']]), '<input type="text" name="name" />')
+        self.assertHTMLEqual('\n'.join(str(bf) for bf in f['name']), '<input type="text" name="name" />')
 
     def test_forms_with_multiple_choice(self):
         # MultipleChoiceField is a special case, as its data is required to be a list:

tests/forms_tests/tests/test_formsets.py

@@ -900,7 +900,7 @@ class FormsFormsetTestCase(TestCase):
         }
         formset = AnotherChoiceFormSet(data, auto_id=False, prefix='choices')
         self.assertTrue(formset.is_valid())
-        self.assertTrue(all([form.is_valid_called for form in formset.forms]))
+        self.assertTrue(all(form.is_valid_called for form in formset.forms))
 
     def test_hard_limit_on_instantiated_forms(self):
         """A formset has a hard limit on the number of forms instantiated."""

tests/forms_tests/tests/test_widgets.py

@@ -640,7 +640,7 @@ beatle J R Ringo False""")
         # You can create your own custom renderers for RadioSelect to use.
         class MyRenderer(RadioFieldRenderer):
            def render(self):
-               return '<br />\n'.join([six.text_type(choice) for choice in self])
+               return '<br />\n'.join(six.text_type(choice) for choice in self)
         w = RadioSelect(renderer=MyRenderer)
         self.assertHTMLEqual(w.render('beatle', 'G', choices=(('J', 'John'), ('P', 'Paul'), ('G', 'George'), ('R', 'Ringo'))), """<label><input type="radio" name="beatle" value="J" /> John</label><br />
 <label><input type="radio" name="beatle" value="P" /> Paul</label><br />
@@ -835,17 +835,17 @@ beatle J R Ringo False""")
 
     def test_subwidget(self):
         # Each subwidget tag gets a separate ID when the widget has an ID specified
-        self.assertHTMLEqual("\n".join([c.tag() for c in CheckboxSelectMultiple(attrs={'id': 'abc'}).subwidgets('letters', list('ac'), choices=zip(list('abc'), list('ABC')))]), """<input checked="checked" type="checkbox" name="letters" value="a" id="abc_0" />
+        self.assertHTMLEqual("\n".join(c.tag() for c in CheckboxSelectMultiple(attrs={'id': 'abc'}).subwidgets('letters', list('ac'), choices=zip(list('abc'), list('ABC')))), """<input checked="checked" type="checkbox" name="letters" value="a" id="abc_0" />
 <input type="checkbox" name="letters" value="b" id="abc_1" />
 <input checked="checked" type="checkbox" name="letters" value="c" id="abc_2" />""")
 
         # Each subwidget tag does not get an ID if the widget does not have an ID specified
-        self.assertHTMLEqual("\n".join([c.tag() for c in CheckboxSelectMultiple().subwidgets('letters', list('ac'), choices=zip(list('abc'), list('ABC')))]), """<input checked="checked" type="checkbox" name="letters" value="a" />
+        self.assertHTMLEqual("\n".join(c.tag() for c in CheckboxSelectMultiple().subwidgets('letters', list('ac'), choices=zip(list('abc'), list('ABC')))), """<input checked="checked" type="checkbox" name="letters" value="a" />
 <input type="checkbox" name="letters" value="b" />
 <input checked="checked" type="checkbox" name="letters" value="c" />""")
 
         # The id_for_label property of the subwidget should return the ID that is used on the subwidget's tag
-        self.assertHTMLEqual("\n".join(['<input type="checkbox" name="letters" value="%s" id="%s" />' % (c.choice_value, c.id_for_label) for c in CheckboxSelectMultiple(attrs={'id': 'abc'}).subwidgets('letters', [], choices=zip(list('abc'), list('ABC')))]), """<input type="checkbox" name="letters" value="a" id="abc_0" />
+        self.assertHTMLEqual("\n".join('<input type="checkbox" name="letters" value="%s" id="%s" />' % (c.choice_value, c.id_for_label) for c in CheckboxSelectMultiple(attrs={'id': 'abc'}).subwidgets('letters', [], choices=zip(list('abc'), list('ABC')))), """<input type="checkbox" name="letters" value="a" id="abc_0" />
 <input type="checkbox" name="letters" value="b" id="abc_1" />
 <input type="checkbox" name="letters" value="c" id="abc_2" />""")
 

tests/proxy_models/tests.py

@@ -79,7 +79,7 @@ class ProxyModelTests(TestCase):
         Person.objects.create(name="Foo McBar")
         MyPerson.objects.create(name="Bazza del Frob")
         LowerStatusPerson.objects.create(status="low", name="homer")
-        pp = sorted([mpp.name for mpp in MyPersonProxy.objects.all()])
+        pp = sorted(mpp.name for mpp in MyPersonProxy.objects.all())
         self.assertEqual(pp, ['Bazza del Frob', 'Foo McBar', 'homer'])
 
     def test_proxy_included_in_ancestors(self):

tests/schema/tests.py

@@ -42,7 +42,7 @@ class SchemaTests(TransactionTestCase):
                             "table": connection.ops.quote_name(field.rel.through._meta.db_table),
                         })
                     except DatabaseError as e:
-                        if any([s in str(e).lower() for s in self.no_table_strings]):
+                        if any(s in str(e).lower() for s in self.no_table_strings):
                             pass
                         else:
                             raise
@@ -53,7 +53,7 @@ class SchemaTests(TransactionTestCase):
                         "table": connection.ops.quote_name(model._meta.db_table),
                     })
                 except DatabaseError as e:
-                    if any([s in str(e).lower() for s in self.no_table_strings]):
+                    if any(s in str(e).lower() for s in self.no_table_strings):
                         pass
                     else:
                         raise

tests/servers/views.py

@@ -8,7 +8,7 @@ def example_view(request):
 
 def model_view(request):
     people = Person.objects.all()
-    return HttpResponse('\n'.join([person.name for person in people]))
+    return HttpResponse('\n'.join(person.name for person in people))
 
 
 def create_model_instance(request):
@@ -18,4 +18,4 @@ def create_model_instance(request):
 
 
 def environ_view(request):
-    return HttpResponse("\n".join(["%s: %r" % (k, v) for k, v in request.environ.items()]))
+    return HttpResponse("\n".join("%s: %r" % (k, v) for k, v in request.environ.items()))

tests/syndication/tests.py

@@ -15,7 +15,7 @@ class FeedTestCase(TestCase):
     fixtures = ['feeddata.json']
 
     def assertChildNodes(self, elem, expected):
-        actual = set([n.nodeName for n in elem.childNodes])
+        actual = set(n.nodeName for n in elem.childNodes)
         expected = set(expected)
         self.assertEqual(actual, expected)
 

tests/template_tests/templatetags/custom.py

@@ -64,13 +64,13 @@ simple_one_default.anything = "Expected simple_one_default __dict__"
 @register.simple_tag
 def simple_unlimited_args(one, two='hi', *args):
     """Expected simple_unlimited_args __doc__"""
-    return "simple_unlimited_args - Expected result: %s" % (', '.join([six.text_type(arg) for arg in [one, two] + list(args)]))
+    return "simple_unlimited_args - Expected result: %s" % (', '.join(six.text_type(arg) for arg in [one, two] + list(args)))
 simple_unlimited_args.anything = "Expected simple_unlimited_args __dict__"
 
 @register.simple_tag
 def simple_only_unlimited_args(*args):
     """Expected simple_only_unlimited_args __doc__"""
-    return "simple_only_unlimited_args - Expected result: %s" % ', '.join([six.text_type(arg) for arg in args])
+    return "simple_only_unlimited_args - Expected result: %s" % ', '.join(six.text_type(arg) for arg in args)
 simple_only_unlimited_args.anything = "Expected simple_only_unlimited_args __dict__"
 
 @register.simple_tag
@@ -79,8 +79,8 @@ def simple_unlimited_args_kwargs(one, two='hi', *args, **kwargs):
     # Sort the dictionary by key to guarantee the order for testing.
     sorted_kwarg = sorted(six.iteritems(kwargs), key=operator.itemgetter(0))
     return "simple_unlimited_args_kwargs - Expected result: %s / %s" % (
-        ', '.join([six.text_type(arg) for arg in [one, two] + list(args)]),
+        ', '.join(six.text_type(arg) for arg in [one, two] + list(args)),
-        ', '.join(['%s=%s' % (k, v) for (k, v) in sorted_kwarg])
+        ', '.join('%s=%s' % (k, v) for (k, v) in sorted_kwarg)
         )
 simple_unlimited_args_kwargs.anything = "Expected simple_unlimited_args_kwargs __dict__"
 
@@ -191,25 +191,25 @@ inclusion_one_default_from_template.anything = "Expected inclusion_one_default_f
 @register.inclusion_tag('inclusion.html')
 def inclusion_unlimited_args(one, two='hi', *args):
     """Expected inclusion_unlimited_args __doc__"""
-    return {"result": "inclusion_unlimited_args - Expected result: %s" % (', '.join([six.text_type(arg) for arg in [one, two] + list(args)]))}
+    return {"result": "inclusion_unlimited_args - Expected result: %s" % (', '.join(six.text_type(arg) for arg in [one, two] + list(args)))}
 inclusion_unlimited_args.anything = "Expected inclusion_unlimited_args __dict__"
 
 @register.inclusion_tag(get_template('inclusion.html'))
 def inclusion_unlimited_args_from_template(one, two='hi', *args):
     """Expected inclusion_unlimited_args_from_template __doc__"""
-    return {"result": "inclusion_unlimited_args_from_template - Expected result: %s" % (', '.join([six.text_type(arg) for arg in [one, two] + list(args)]))}
+    return {"result": "inclusion_unlimited_args_from_template - Expected result: %s" % (', '.join(six.text_type(arg) for arg in [one, two] + list(args)))}
 inclusion_unlimited_args_from_template.anything = "Expected inclusion_unlimited_args_from_template __dict__"
 
 @register.inclusion_tag('inclusion.html')
 def inclusion_only_unlimited_args(*args):
     """Expected inclusion_only_unlimited_args __doc__"""
-    return {"result": "inclusion_only_unlimited_args - Expected result: %s" % (', '.join([six.text_type(arg) for arg in args]))}
+    return {"result": "inclusion_only_unlimited_args - Expected result: %s" % (', '.join(six.text_type(arg) for arg in args))}
 inclusion_only_unlimited_args.anything = "Expected inclusion_only_unlimited_args __dict__"
 
 @register.inclusion_tag(get_template('inclusion.html'))
 def inclusion_only_unlimited_args_from_template(*args):
     """Expected inclusion_only_unlimited_args_from_template __doc__"""
-    return {"result": "inclusion_only_unlimited_args_from_template - Expected result: %s" % (', '.join([six.text_type(arg) for arg in args]))}
+    return {"result": "inclusion_only_unlimited_args_from_template - Expected result: %s" % (', '.join(six.text_type(arg) for arg in args))}
 inclusion_only_unlimited_args_from_template.anything = "Expected inclusion_only_unlimited_args_from_template __dict__"
 
 @register.inclusion_tag('test_incl_tag_current_app.html', takes_context=True)
@@ -230,8 +230,8 @@ def inclusion_unlimited_args_kwargs(one, two='hi', *args, **kwargs):
     # Sort the dictionary by key to guarantee the order for testing.
     sorted_kwarg = sorted(six.iteritems(kwargs), key=operator.itemgetter(0))
     return {"result": "inclusion_unlimited_args_kwargs - Expected result: %s / %s" % (
-        ', '.join([six.text_type(arg) for arg in [one, two] + list(args)]),
+        ', '.join(six.text_type(arg) for arg in [one, two] + list(args)),
-        ', '.join(['%s=%s' % (k, v) for (k, v) in sorted_kwarg])
+        ', '.join('%s=%s' % (k, v) for (k, v) in sorted_kwarg)
         )}
 inclusion_unlimited_args_kwargs.anything = "Expected inclusion_unlimited_args_kwargs __dict__"
 
@@ -286,13 +286,13 @@ assignment_one_default.anything = "Expected assignment_one_default __dict__"
 @register.assignment_tag
 def assignment_unlimited_args(one, two='hi', *args):
     """Expected assignment_unlimited_args __doc__"""
-    return "assignment_unlimited_args - Expected result: %s" % (', '.join([six.text_type(arg) for arg in [one, two] + list(args)]))
+    return "assignment_unlimited_args - Expected result: %s" % (', '.join(six.text_type(arg) for arg in [one, two] + list(args)))
 assignment_unlimited_args.anything = "Expected assignment_unlimited_args __dict__"
 
 @register.assignment_tag
 def assignment_only_unlimited_args(*args):
     """Expected assignment_only_unlimited_args __doc__"""
-    return "assignment_only_unlimited_args - Expected result: %s" % ', '.join([six.text_type(arg) for arg in args])
+    return "assignment_only_unlimited_args - Expected result: %s" % ', '.join(six.text_type(arg) for arg in args)
 assignment_only_unlimited_args.anything = "Expected assignment_only_unlimited_args __dict__"
 
 @register.assignment_tag
@@ -301,8 +301,8 @@ def assignment_unlimited_args_kwargs(one, two='hi', *args, **kwargs):
     # Sort the dictionary by key to guarantee the order for testing.
     sorted_kwarg = sorted(six.iteritems(kwargs), key=operator.itemgetter(0))
     return "assignment_unlimited_args_kwargs - Expected result: %s / %s" % (
-        ', '.join([six.text_type(arg) for arg in [one, two] + list(args)]),
+        ', '.join(six.text_type(arg) for arg in [one, two] + list(args)),
-        ', '.join(['%s=%s' % (k, v) for (k, v) in sorted_kwarg])
+        ', '.join('%s=%s' % (k, v) for (k, v) in sorted_kwarg)
         )
 assignment_unlimited_args_kwargs.anything = "Expected assignment_unlimited_args_kwargs __dict__"
 

tests/template_tests/tests.py

@@ -507,7 +507,7 @@ class TemplateTests(TransRealMixin, TestCase):
         template_tests.update(filter_tests)
 
         cache_loader = setup_test_template_loader(
-            dict([(name, t[0]) for name, t in six.iteritems(template_tests)]),
+            dict((name, t[0]) for name, t in six.iteritems(template_tests)),
             use_cached_loader=True,
         )