      """A wrapper that provides direct key access to context items contained
      in a list of context objects.
      """
      def __getitem__(self, key):
          if isinstance(key, six.string_types):
              for subcontext in self:
                  if key in subcontext:
                      return subcontext[key]
              raise KeyError(key)
          else:
 
</s> remove                 if isinstance(items, six.string_types):
 </s> add                 if isinstance(items, str): </s> remove             output += ''.join(six.text_type(c) for c in self.children)
 </s> add             output += ''.join(str(c) for c in self.children) </s> remove         elif isinstance(unique, six.string_types):
 </s> add         elif isinstance(unique, str): </s> remove             lists = [[six.text_type(r) for r in a.first_book.read_by.all()]
 </s> add             lists = [[str(r) for r in a.first_book.read_by.all()] </s> remove         if not isinstance(index, (slice,) + six.integer_types):
 </s> add         if not isinstance(index, (int, slice)):
        if isinstance(key, str):
      """A wrapper that provides direct key access to context items contained
      in a list of context objects.
      """
      def __getitem__(self, key):
        if isinstance(key, str):
              for subcontext in self:
                  if key in subcontext:
                      return subcontext[key]
              raise KeyError(key)
          else:
keep keep keep keep replace keep keep keep keep keep
 Refs #23919 -- Removed six.<various>_types usage

Thanks Tim Graham and Simon Charette for the reviews. 
django/test/utils.py