Разликата между __ул. " __ и __repr__

very briefly
 - The default implementation is useless (it’s hard to think of one which wouldn’t be, but yeah)
 - __repr__ goal is to be unambiguous
 - __str__ goal is to be readable
 - Container’s __str__ uses contained objects’ __repr__
 
see source for more info

>>> import datetime
>>> now = datetime.datetime.now()
>>> now.__str__()
'2020-12-27 22:28:00.324317'
>>> now.__repr__()
'datetime.datetime(2020, 12, 27, 22, 28, 0, 324317)'