Add support of SimpleNamespace in copy.replace()

[serhiy-storchaka]

Feature or enhancement

SimpleNamespace is used as a simple data record type, a simpler alternative to named tuples and dataclasses. Although it is easy to create a copy of a SimpleNamespace instance with modified attributes (SimpleNamespace(**vars(ns), attr=newvalue)), it would be convenient if SimpleNamespace be supported in copy.replace() which already supports named tuples and dataclasses.

#108751
https://discuss.python.org/t/generalize-replace-function/28511

Linked PRs

• gh-109174: Add support of SimpleNamespace in copy.replace() #109175

[serhiy-storchaka]

The implementation in #109175 is equivalent to

def __replace__(self, /, **kwargs):
    result = type(self)()
    result.__dict__.update(self.__dict__)
    result.__dict__.update(kwargs)
    return result

It does not pass arguments to the constructor, but this is consistent with pickling and copying. In any case, a SimpleNmaespace subclass with constructor is very unusual.

cc @ericsnowcurrently