custom python datetime object with default format

customdate.py

# Custom datetime class that can be initialized by date string and has default format
# useful for automatic serialization/deserializaion (to JSON, or other formats) such that
# when deserialized constructore can be called directly CustomDate(<string>) and serialization is just str()

import datetime

class CustomDate(datetime.datetime):
    __date_format = '%Y/%m/%d'

    def __new__(cls, *args, **kwargs):
        if args and type(args[0]) == str:
            d = datetime.datetime.strptime(args[0], cls.__date_format)
            me = super().__new__(cls, d.year, d.month, d.day, d.hour, d.minute, d.second)
        else:
            me = super().__new__(cls, *args, **kwargs)

        return me

    def __repr__(self):
        return self.__format__(self.__date_format)


if __name__ == '__main__':
    a = CustomDate('2019/1/1')
    b = CustomDate(2019, 1, 1)

    print(a)
    print(b)