Feature or enhancement

Has this already been discussed elsewhere?

I have already discussed this feature proposal on Discourse

Links to previous discussion of this feature:

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

Proposal:

Some classes have thereplace() method, which creates a modified copy of the object (modified values are provided as keyword arguments). Named tuples have the_replace() for this (to avoid conflict with attributereplace). Dataclasses provide a global function for this.

I proposed to generalizedataclasses.replace() to support all classes which need this feature. By the result of the discussion on discuss.python.org, the new function will be added in thecopy module ascopy.replace().dataclasses.replace() will continue to support only dataclasses. Dataclasses, named tuples and all classes which currently have thereplace() method with suitable semantic will get also the__replace__() method. Now you can add such feature in new classes without conflicting with thereplace attribute, and use this feature in general code without conflicting withstr.replace() and like.

For now,copy.replace() is more limited thancopy.copy() and does not fall back to use the powerful pickle protocol.

Linked PRs

• gh-108751: Add copy.replace() function #108752