code: def parse_magnitude(self, magnitude_str):
          
          symbol = magnitude_str[0].strip()
          magnitude = magnitude_str[1:6].strip()
          return float(magnitude) if magnitude else None, symbol
docs: Converts magnitude field to a float value, or ``None`` if GCVS does
          not list the magnitude.
  
          Returns a tuple (magnitude, symbol), where symbol can be either an
          empty string or a single character - one of '<', '>', '('.