docs: def parse_price(price_string):
      """
      >>> parse_price('£16,000.00')
      16000.0
      >>> parse_price('-£16,000.00')
      -16000.0
      """
      return float(re.sub('[£,]', '', price_string))
  
      match = re.match('(?P<amount>-?£[\d,]+(\.\d{2})?)', price_string)
      if not match:
          raise ValueError("Charge not in format '(-)£16,000(.00)' : {}".format(
              repr(price_string)))
      return float(re.sub('[£,]', '', match.group('amount')))