  
          if isinstance(value, datetime.datetime):
              return self.enforce_timezone(value)
  
          for format in self.input_formats:
              if format.lower() == ISO_8601:
                  try:
                      parsed = parse_datetime(value)
                  except (ValueError, TypeError):
                      pass
                  else:
 
</s> remove         for format in self.input_formats:
            if format.lower() == ISO_8601:
 </s> add         for input_format in input_formats:
            if input_format.lower() == ISO_8601: </s> remove         for format in self.input_formats:
            if format.lower() == ISO_8601:
 </s> add         for input_format in input_formats:
            if input_format.lower() == ISO_8601: </s> remove                     parsed = self.datetime_parser(value, format)
 </s> add                     parsed = self.datetime_parser(value, input_format) </s> remove                     parsed = self.datetime_parser(value, format)
 </s> add                     parsed = self.datetime_parser(value, input_format) </s> remove                     parsed = self.datetime_parser(value, format)
 </s> add                     parsed = self.datetime_parser(value, input_format)
        for input_format in input_formats:
            if input_format.lower() == ISO_8601:
  
          if isinstance(value, datetime.datetime):
              return self.enforce_timezone(value)
  
        for input_format in input_formats:
            if input_format.lower() == ISO_8601:
        for input_format in input_formats:
            if input_format.lower() == ISO_8601:
                  try:
                      parsed = parse_datetime(value)
                  except (ValueError, TypeError):
                      pass
                  else:
keep keep keep keep replace replace keep keep keep keep keep
 Access settings lazily, not at module import 
rest_framework/fields.py