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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Make TypeAliasType __module__ attribute writable","articleBody":"# Feature or enhancement\n\n### Proposal:\n\nMake the `__module__` attribute on `TypeAliasType` writable. This allows users to overwrite the attribute when frame introspection gets it wrong.\n\n### Motivation\n\n`typing.TypeAliasType` currently derives `__module__` from a [frame walk](https://github.com/python/cpython/blob/d71e3bc5a0f2f7af407eb32a8a5b36acf66070aa/Objects/typevarobject.c#L391). This is unsuitable when constructing TypeAliasType objects inside exec, from C, or with a factory helper. In such cases frame introspection returns None or the wrong module.\n\nThere is currently no way to fix this after the fact, because `__module__` is read-only:\n\n```py\n\u003e\u003e\u003e from typing import TypeAliasType\n\u003e\u003e\u003e ta = TypeAliasType(\"A\", int)\n\u003e\u003e\u003e ta.__module__ = \"x\"\nAttributeError: attribute '__module__' of 'typing.TypeAliasType' objects is not writable\n```\n\nMeanwhile there are consumers that rely on `__module__`, such as IDE go-to-definition or introspection-based stub generation (e.g. with `f\"{alias.__module__}.{alias.__name__}\"`). Such tools have no good recourse when `__module__` is wrong.\n\n### Has this already been discussed elsewhere?\n\nI have already discussed this feature proposal on Discourse\n\n### Links to previous discussion of this feature:\n\nhttps://discuss.python.org/t/adding-a-module-keyword-argument-to-typing-typealiastype/107087\n\n\u003c!-- gh-linked-prs --\u003e\n### Linked PRs\n* gh-149172\n\u003c!-- /gh-linked-prs --\u003e\n","author":{"url":"https://github.com/ericmarkmartin","@type":"Person","name":"ericmarkmartin"},"datePublished":"2026-04-30T05:28:14.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/149171/cpython/issues/149171"}