René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"`typing.Annotated[int, ...]` is subclassable","articleBody":"You can subclass `Annotated[int, \"meta\"]`:\r\n\r\n```python\r\n\u003e\u003e\u003e import typing\r\n\u003e\u003e\u003e class Some(typing.Annotated[int, 'meta']): ...\r\n... \r\n\u003e\u003e\u003e Some.__mro__\r\n(\u003cclass '__main__.Some'\u003e, \u003cclass 'int'\u003e, \u003cclass 'object'\u003e)\r\n```\r\n\r\nBut, here are a couple of problems:\r\n1. All metadata is lost: so, no reason to use `Annotated` in the first place\r\n2. https://peps.python.org/pep-0593/ never mentions this use-case\r\n3. We assume that `Annotated` cannot be subclassed: https://github.com/python/cpython/blame/53a54b781d1f05f2d0b40ce88b3da92d5d23e9d2/Lib/test/test_typing.py#L6562-L6565 here\r\n\r\nI think that `Annotated` should not be subclasses and this is a bug.\r\nThe PR is incoming :)\r\n\r\nI found this while working on https://github.com/python/cpython/issues/96769","author":{"url":"https://github.com/sobolevn","@type":"Person","name":"sobolevn"},"datePublished":"2022-09-12T10:48:09.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":6},"url":"https://github.com/96771/cpython/issues/96771"}