Message 125979 - Python tracker
Note that before r82065, python prototype, now available as Lib/datetime.py had binary operations implemented to return subclass instances. Here is annotated pre-r82065 code: 39876 gvanrossum def __add__(self, other): 39876 gvanrossum if isinstance(other, timedelta): 39928 gvanrossum return self.__class__(self.__days + other.__days, 39876 gvanrossum self.__seconds + other.__seconds, 39876 gvanrossum self.__microseconds + other.__microseconds) 40207 tim_one return NotImplemented 39876 gvanrossum