              "The `source` argument is not meaningful when applied to a `child=` field. "
              "Remove `source=` from the field declaration."
          )
  
          super(DictField, self).__init__(*args, **kwargs)
          self.child.bind(field_name='', parent=self)
  
      def get_value(self, dictionary):
          # We override the default field access in order to support
          # dictionaries in HTML forms.
 
</s> remove         super(ManyRelatedField, self).__init__(*args, **kwargs)
 </s> add         super().__init__(*args, **kwargs) </s> remove         return super(BaseSerializer, cls).__new__(cls, *args, **kwargs)
 </s> add         return super().__new__(cls, *args, **kwargs) </s> remove         return super(RelatedField, cls).__new__(cls, *args, **kwargs)
 </s> add         return super().__new__(cls, *args, **kwargs) </s> remove         super(RelatedField, self).__init__(**kwargs)
 </s> add         super().__init__(**kwargs) </s> remove class UniqueValidator(object):
 </s> add class UniqueValidator:
        super().__init__(*args, **kwargs)
              "The `source` argument is not meaningful when applied to a `child=` field. "
              "Remove `source=` from the field declaration."
          )
  
        super().__init__(*args, **kwargs)
          self.child.bind(field_name='', parent=self)
  
      def get_value(self, dictionary):
          # We override the default field access in order to support
          # dictionaries in HTML forms.
keep keep keep keep replace keep keep keep keep keep
 Dropped Python 2 compatibility. (#6615)

Thanks to Jon Dufresne (@jdufresne) for review.

Co-authored-by: Asif Saif Uddin <auvipy@gmail.com>
Co-authored-by: Rizwan Mansuri <Rizwan@webbyfox.com> 
rest_framework/fields.py