old_contents: import sys
  import django
  
  __all__ = ['DEFAULT_TIMEOUT', 'FOREVER', 'u', 'basestring_']
  
  
  if django.VERSION[:2] >= (1, 6):
      from django.core.cache.backends.base import DEFAULT_TIMEOUT as DJANGO_DEFAULT_TIMEOUT
      DEFAULT_TIMEOUT = DJANGO_DEFAULT_TIMEOUT
      FOREVER = None
  else:
      DEFAULT_TIMEOUT = None
      FOREVER = 0
  
  if sys.version_info < (3,):
      import codecs
      def u(x):
          return codecs.unicode_escape_decode(x)[0]
      basestring_ = basestring
  else:
      def u(x):
          return x
      basestring_ = str
  
new_contents: import sys
  import django
  
  __all__ = ['DEFAULT_TIMEOUT', 'FOREVER', 'u', 'basestring_']
  
  
  if django.VERSION[:2] >= (1, 6):
      from django.core.cache.backends.base import DEFAULT_TIMEOUT as DJANGO_DEFAULT_TIMEOUT
      DEFAULT_TIMEOUT = DJANGO_DEFAULT_TIMEOUT
      FOREVER = None
  else:
      DEFAULT_TIMEOUT = None
      FOREVER = 0
  
  if sys.version_info < (3,):
      import codecs
  
      def u(x):
          return codecs.unicode_escape_decode(x)[0]
      basestring_ = basestring  # flake8: noqa
  else:
      def u(x):
          return x
      basestring_ = str
  
subject: correct flake8 error