code: def parse(cls, s):
          
          try:
              numbers = map(int, s.split("-"))
          except (ValueError, AttributeError):
              raise ValueError("Date string must be in format YYYY-MM-DD")
          else:
              numbers = list(numbers)
              if len(numbers) == 3:
                  return cls(*numbers)
              raise ValueError("Date string must be in format YYYY-MM-DD")
docs: Parse a string to produce a :class:`.Date`.
  
          Accepted formats:
              'YYYY-MM-DD'
  
          :param s:
          :return: