Refs #23919 -- Removed most of remaining six usage

Thanks Tim Graham for the review.

django/db/backends/base/base.py

@@ -4,6 +4,7 @@ import warnings
 from collections import deque
 from contextlib import contextmanager
 
+import _thread
 import pytz
 
 from django.conf import settings
@@ -16,7 +17,6 @@ from django.db.transaction import TransactionManagementError
 from django.db.utils import DatabaseError, DatabaseErrorWrapper
 from django.utils import timezone
 from django.utils.functional import cached_property
-from django.utils.six.moves import _thread as thread
 
 NO_DB_ALIAS = '__no_db__'
 
@@ -82,7 +82,7 @@ class BaseDatabaseWrapper(object):
 
         # Thread-safety related attributes.
         self.allow_thread_sharing = allow_thread_sharing
-        self._thread_ident = thread.get_ident()
+        self._thread_ident = _thread.get_ident()
 
         # A list of no-argument functions to run when the transaction commits.
         # Each entry is an (sids, func) tuple, where sids is a set of the
@@ -326,7 +326,7 @@ class BaseDatabaseWrapper(object):
         if not self._savepoint_allowed():
             return
 
-        thread_ident = thread.get_ident()
+        thread_ident = _thread.get_ident()
         tid = str(thread_ident).replace('-', '')
 
         self.savepoint_state += 1
@@ -533,13 +533,13 @@ class BaseDatabaseWrapper(object):
         authorized to be shared between threads (via the `allow_thread_sharing`
         property). Raises an exception if the validation fails.
         """
-        if not (self.allow_thread_sharing or self._thread_ident == thread.get_ident()):
+        if not (self.allow_thread_sharing or self._thread_ident == _thread.get_ident()):
             raise DatabaseError(
                 "DatabaseWrapper objects created in a "
                 "thread can only be used in that same thread. The object "
                 "with alias '%s' was created in thread id %s and this is "
                 "thread id %s."
-                % (self.alias, self._thread_ident, thread.get_ident())
+                % (self.alias, self._thread_ident, _thread.get_ident())
             )
 
     # ##### Miscellaneous #####

django/db/backends/base/creation.py

@@ -1,11 +1,10 @@
 import sys
+from io import StringIO
 
 from django.apps import apps
 from django.conf import settings
 from django.core import serializers
 from django.db import router
-from django.utils.six import StringIO
-from django.utils.six.moves import input
 
 # The prefix to put on the default database name when creating
 # the test database.

django/db/backends/oracle/base.py

@@ -516,7 +516,7 @@ class FormatStylePlaceholderCursor(object):
         return CursorIterator(self.cursor)
 
 
-class CursorIterator(six.Iterator):
+class CursorIterator:
     """
     Cursor iterator wrapper that invokes our custom row factory.
     """

django/db/backends/oracle/creation.py

@@ -5,7 +5,6 @@ from django.db.backends.base.creation import BaseDatabaseCreation
 from django.db.utils import DatabaseError
 from django.utils.crypto import get_random_string
 from django.utils.functional import cached_property
-from django.utils.six.moves import input
 
 TEST_DATABASE_PREFIX = 'test_'
 

django/db/backends/postgresql/client.py

@@ -3,7 +3,6 @@ import subprocess
 
 from django.core.files.temp import NamedTemporaryFile
 from django.db.backends.base.client import BaseDatabaseClient
-from django.utils.six import print_
 
 
 def _escape_pgpass(txt):
@@ -40,7 +39,7 @@ class DatabaseClient(BaseDatabaseClient):
                 # Create temporary .pgpass file.
                 temp_pgpass = NamedTemporaryFile(mode='w+')
                 try:
-                    print_(
+                    print(
                         _escape_pgpass(host) or '*',
                         str(port) or '*',
                         _escape_pgpass(dbname) or '*',

django/db/backends/sqlite3/creation.py

@@ -5,7 +5,6 @@ import sys
 from django.core.exceptions import ImproperlyConfigured
 from django.db.backends.base.creation import BaseDatabaseCreation
 from django.utils.encoding import force_text
-from django.utils.six.moves import input
 
 
 class DatabaseCreation(BaseDatabaseCreation):

django/db/migrations/loader.py

@@ -1,6 +1,6 @@
 import os
 import sys
-from importlib import import_module
+from importlib import import_module, reload
 
 from django.apps import apps
 from django.conf import settings
@@ -97,7 +97,7 @@ class MigrationLoader(object):
                     continue
                 # Force a reload if it's already loaded (tests need this)
                 if was_loaded:
-                    six.moves.reload_module(module)
+                    reload(module)
             self.migrated_apps.add(app_config.label)
             directory = os.path.dirname(module.__file__)
             # Scan for .py files

django/db/migrations/questioner.py

@@ -5,7 +5,6 @@ import sys
 from django.apps import apps
 from django.db.models.fields import NOT_PROVIDED
 from django.utils import datetime_safe, timezone
-from django.utils.six.moves import input
 
 from .loader import MigrationLoader
 

django/db/migrations/serializer.py

@@ -1,3 +1,4 @@
+import builtins
 import collections
 import datetime
 import decimal
@@ -10,7 +11,7 @@ from importlib import import_module
 from django.db import models
 from django.db.migrations.operations.base import Operation
 from django.db.migrations.utils import COMPILED_REGEX_TYPE, RegexObject
-from django.utils import datetime_safe, six
+from django.utils import datetime_safe
 from django.utils.encoding import force_text
 from django.utils.functional import LazyObject, Promise
 from django.utils.timezone import utc
@@ -305,7 +306,7 @@ class TypeSerializer(BaseSerializer):
                 return string, set(imports)
         if hasattr(self.value, "__module__"):
             module = self.value.__module__
-            if module == six.moves.builtins.__name__:
+            if module == builtins.__name__:
                 return self.value.__name__, set()
             else:
                 return "%s.%s" % (module, self.value.__name__), {"import %s" % module}

django/db/models/base.py

@@ -26,10 +26,8 @@ from django.db.models.signals import (
     class_prepared, post_init, post_save, pre_init, pre_save,
 )
 from django.db.models.utils import make_model_tuple
-from django.utils import six
 from django.utils.encoding import force_str, force_text
 from django.utils.functional import curry
-from django.utils.six.moves import zip
 from django.utils.text import capfirst, get_text_list
 from django.utils.translation import ugettext_lazy as _
 from django.utils.version import get_version
@@ -385,7 +383,7 @@ class ModelState(object):
         self.adding = True
 
 
-class Model(six.with_metaclass(ModelBase)):
+class Model(metaclass=ModelBase):
 
     def __init__(self, *args, **kwargs):
         # Alias some things as locals to avoid repeat global lookups

django/db/models/deletion.py

@@ -3,7 +3,6 @@ from operator import attrgetter
 
 from django.db import IntegrityError, connections, transaction
 from django.db.models import signals, sql
-from django.utils import six
 
 
 class ProtectedError(IntegrityError):
@@ -198,7 +197,7 @@ class Collector(object):
             # Recursively collect concrete model's parent models, but not their
             # related objects. These will be found by meta.get_fields()
             concrete_model = model._meta.concrete_model
-            for ptr in six.itervalues(concrete_model._meta.parents):
+            for ptr in concrete_model._meta.parents.values():
                 if ptr:
                     parent_objs = [getattr(obj, ptr.name) for obj in new_objs]
                     self.collect(parent_objs, source=model,
@@ -236,7 +235,7 @@ class Collector(object):
         )
 
     def instances_with_model(self):
-        for model, instances in six.iteritems(self.data):
+        for model, instances in self.data.items():
             for obj in instances:
                 yield model, obj
 
@@ -285,18 +284,18 @@ class Collector(object):
                 deleted_counter[qs.model._meta.label] += count
 
             # update fields
-            for model, instances_for_fieldvalues in six.iteritems(self.field_updates):
+            for model, instances_for_fieldvalues in self.field_updates.items():
                 query = sql.UpdateQuery(model)
-                for (field, value), instances in six.iteritems(instances_for_fieldvalues):
+                for (field, value), instances in instances_for_fieldvalues.items():
                     query.update_batch([obj.pk for obj in instances],
                                        {field.name: value}, self.using)
 
             # reverse instance collections
-            for instances in six.itervalues(self.data):
+            for instances in self.data.values():
                 instances.reverse()
 
             # delete instances
-            for model, instances in six.iteritems(self.data):
+            for model, instances in self.data.items():
                 query = sql.DeleteQuery(model)
                 pk_list = [obj.pk for obj in instances]
                 count = query.delete_batch(pk_list, self.using)
@@ -309,11 +308,11 @@ class Collector(object):
                         )
 
         # update collected instances
-        for model, instances_for_fieldvalues in six.iteritems(self.field_updates):
-            for (field, value), instances in six.iteritems(instances_for_fieldvalues):
+        for model, instances_for_fieldvalues in self.field_updates.items():
+            for (field, value), instances in instances_for_fieldvalues.items():
                 for obj in instances:
                     setattr(obj, field.attname, value)
-        for model, instances in six.iteritems(self.data):
+        for model, instances in self.data.items():
             for instance in instances:
                 setattr(instance, model._meta.pk.attname, None)
         return sum(deleted_counter.values()), dict(deleted_counter)

django/db/models/lookups.py

@@ -10,7 +10,6 @@ from django.db.models.fields import (
 )
 from django.db.models.query_utils import RegisterLookupMixin
 from django.utils.functional import cached_property
-from django.utils.six.moves import range
 
 
 class Lookup(object):

django/db/models/options.py

@@ -13,7 +13,6 @@ from django.db.models.fields import AutoField
 from django.db.models.fields.proxy import OrderWrt
 from django.db.models.fields.related import OneToOneField
 from django.db.models.query_utils import PathInfo
-from django.utils import six
 from django.utils.datastructures import ImmutableList, OrderedSet
 from django.utils.deprecation import RemovedInDjango21Warning
 from django.utils.encoding import force_text
@@ -228,7 +227,7 @@ class Options(object):
             if self.parents:
                 # Promote the first parent link in lieu of adding yet another
                 # field.
-                field = next(six.itervalues(self.parents))
+                field = next(iter(self.parents.values()))
                 # Look for a local field with the same name as the
                 # first parent link. If a local field has already been
                 # created, use it instead of promoting the parent

django/db/models/query.py

@@ -480,7 +480,7 @@ class QuerySet(object):
                 obj, created = self._create_object_from_params(lookup, params)
                 if created:
                     return obj, created
-            for k, v in six.iteritems(defaults):
+            for k, v in defaults.items():
                 setattr(obj, k, v() if callable(v) else v)
             obj.save(using=self.db)
         return obj, False
@@ -1170,7 +1170,7 @@ class InstanceCheckMeta(type):
         return isinstance(instance, QuerySet) and instance.query.is_empty()
 
 
-class EmptyQuerySet(six.with_metaclass(InstanceCheckMeta)):
+class EmptyQuerySet(metaclass=InstanceCheckMeta):
     """
     Marker class usable for checking if a queryset is empty by .none():
         isinstance(qs.none(), EmptyQuerySet) -> True

django/db/models/sql/compiler.py

@@ -11,7 +11,6 @@ from django.db.models.sql.constants import (
 from django.db.models.sql.query import Query, get_order_dir
 from django.db.transaction import TransactionManagementError
 from django.db.utils import DatabaseError
-from django.utils.six.moves import zip
 
 FORCE = object()
 

django/db/models/sql/query.py

@@ -30,7 +30,6 @@ from django.db.models.sql.datastructures import (
 from django.db.models.sql.where import (
     AND, OR, ExtraWhere, NothingNode, WhereNode,
 )
-from django.utils import six
 from django.utils.encoding import force_text
 from django.utils.tree import Node
 
@@ -104,7 +103,7 @@ class RawQuery(object):
         if params_type is tuple:
             params = tuple(adapter(val) for val in self.params)
         elif params_type is dict:
-            params = dict((key, adapter(val)) for key, val in six.iteritems(self.params))
+            params = {key: adapter(val) for key, val in self.params.items()}
         else:
             raise RuntimeError("Unexpected params type: %s" % params_type)
 
@@ -665,23 +664,23 @@ class Query(object):
             # slight complexity here is handling fields that exist on parent
             # models.
             workset = {}
-            for model, values in six.iteritems(seen):
+            for model, values in seen.items():
                 for field in model._meta.fields:
                     if field in values:
                         continue
                     m = field.model._meta.concrete_model
                     add_to_dict(workset, m, field)
-            for model, values in six.iteritems(must_include):
+            for model, values in must_include.items():
                 # If we haven't included a model in workset, we don't add the
                 # corresponding must_include fields for that model, since an
                 # empty set means "include all fields". That's why there's no
                 # "else" branch here.
                 if model in workset:
                     workset[model].update(values)
-            for model, values in six.iteritems(workset):
+            for model, values in workset.items():
                 callback(target, model, values)
         else:
-            for model, values in six.iteritems(must_include):
+            for model, values in must_include.items():
                 if model in seen:
                     seen[model].update(values)
                 else:
@@ -695,7 +694,7 @@ class Query(object):
             for model in orig_opts.get_parent_list():
                 if model not in seen:
                     seen[model] = set()
-            for model, values in six.iteritems(seen):
+            for model, values in seen.items():
                 callback(target, model, values)
 
     def table_alias(self, table_name, create=False):
@@ -813,7 +812,7 @@ class Query(object):
                 (key, col.relabeled_clone(change_map)) for key, col in self._annotations.items())
 
         # 2. Rename the alias in the internal table/alias datastructures.
-        for old_alias, new_alias in six.iteritems(change_map):
+        for old_alias, new_alias in change_map.items():
             if old_alias not in self.alias_map:
                 continue
             alias_data = self.alias_map[old_alias].relabeled_clone(change_map)
@@ -1698,7 +1697,7 @@ class Query(object):
             self.group_by.append(col)
 
         if self.annotation_select:
-            for alias, annotation in six.iteritems(self.annotation_select):
+            for alias, annotation in self.annotation_select.items():
                 for col in annotation.get_group_by_cols():
                     self.group_by.append(col)
 

django/db/models/sql/subqueries.py

@@ -9,7 +9,6 @@ from django.db.models.sql.constants import (
     CURSOR, GET_ITERATOR_CHUNK_SIZE, NO_RESULTS,
 )
 from django.db.models.sql.query import Query
-from django.utils import six
 
 __all__ = ['DeleteQuery', 'UpdateQuery', 'InsertQuery', 'AggregateQuery']
 
@@ -120,7 +119,7 @@ class UpdateQuery(Query):
         querysets.
         """
         values_seq = []
-        for name, val in six.iteritems(values):
+        for name, val in values.items():
             field = self.get_meta().get_field(name)
             direct = not (field.auto_created and not field.concrete) or not field.concrete
             model = field.model._meta.concrete_model
@@ -164,7 +163,7 @@ class UpdateQuery(Query):
         if not self.related_updates:
             return []
         result = []
-        for model, values in six.iteritems(self.related_updates):
+        for model, values in self.related_updates.items():
             query = UpdateQuery(model)
             query.values = values
             if self.related_ids is not None: