          'no_name': _('No filename could be determined.'),
          'empty': _('The submitted file is empty.'),
          'max_length': _('Ensure this filename has at most {max_length} characters (it has {length}).'),
      }
      use_url = api_settings.UPLOADED_FILES_USE_URL
  
      def __init__(self, *args, **kwargs):
          self.max_length = kwargs.pop('max_length', None)
          self.allow_empty_file = kwargs.pop('allow_empty_file', False)
          self.use_url = kwargs.pop('use_url', self.use_url)
 
</s> remove         self.use_url = kwargs.pop('use_url', self.use_url)
 </s> add         if 'use_url' in kwargs:
            self.use_url = kwargs.pop('use_url') </s> remove     format = api_settings.TIME_FORMAT
    input_formats = api_settings.TIME_INPUT_FORMATS
 </s> add  </s> remove     format = api_settings.DATE_FORMAT
    input_formats = api_settings.DATE_INPUT_FORMATS
 </s> add  </s> remove     coerce_to_string = api_settings.COERCE_DECIMAL_TO_STRING

 </s> add  </s> remove         if self.use_url:
 </s> add         if use_url:
          'no_name': _('No filename could be determined.'),
          'empty': _('The submitted file is empty.'),
          'max_length': _('Ensure this filename has at most {max_length} characters (it has {length}).'),
      }

  
      def __init__(self, *args, **kwargs):
          self.max_length = kwargs.pop('max_length', None)
          self.allow_empty_file = kwargs.pop('allow_empty_file', False)
          self.use_url = kwargs.pop('use_url', self.use_url)
keep keep keep keep replace keep keep keep keep keep
 Access settings lazily, not at module import 
rest_framework/fields.py