  import hashlib
  import operator
  import sys
  
  from django.db.backends.creation import BaseDatabaseCreation
  from django.db.backends.util import truncate_name
  from django.db.models.fields.related import ManyToManyField
  from django.db.transaction import atomic
 
</s> remove from django.utils.http import urlquote
 </s> add  </s> remove import warnings
 </s> add  </s> remove import datetime
from django.utils import six
 </s> add  </s> remove from django.utils._os import upath
 </s> add  </s> remove from django.utils import six
 </s> add 
  import hashlib
  import operator

  
  from django.db.backends.creation import BaseDatabaseCreation
  from django.db.backends.util import truncate_name
  from django.db.models.fields.related import ManyToManyField
  from django.db.transaction import atomic
keep keep replace keep keep keep keep keep
 Fixed a number of flake8 errors -- particularly around unused imports and local variables 
django/db/backends/schema.py