René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Overlapping type","articleBody":"This is an rough idea from the recent discussion of whether to use `object`/`Any` or `_KT` for arguments of certain methods like `pop` or `__sub__`. E.g.:\n\n```python\nclass MyPoppable[KT, VT]:\n    def pop(self, x: X) -\u003e VT: ...\n```\n\nWhat should `X` be? Using `KT` (or `KT | None`) find type errors like the following:\n\n```python\npoppable: MyPoppable[str]\npoppable.pop(123)\n```\n\nBut has a problem with overlapping types:\n\n```python\ndef foo(x: int | str):\n    poppable.pop(x)\n```\n\nOn the other hand, using `object` doesn't catch type errors like `poppable.pop(123)`.\n\nThe solution would be able to specify that any partially overlapping type would be accepted:\n\n```python\nclass MyPoppable[KT, VT]:\n    def pop(self, x: Overlapping[KT]) -\u003e VT: ...\n```\n\n`MyPoppable[str]().pop()` would accept `str`, `str | None`, `Literal[\"x\"]`, `str | int`, etc., but not e.g. plain `int`.","author":{"url":"https://github.com/srittau","@type":"Person","name":"srittau"},"datePublished":"2026-01-19T16:36:07.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/2154/typing/issues/2154"}