René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"min()/max() with default value cause issues with key function type","articleBody":"## Bug Report\r\n\r\nHi everyone, thanks for all the work on mypy, I love this tool! 👏 \r\n\r\nI run into an issue with this code:\r\n\r\n```python\r\ndef foo(values: list[dict]) -\u003e dict | None:\r\n    return max(values, default=None, key=lambda entry: entry.get(\"value\", 0))\r\n```\r\nSee playground: https://mypy-play.net/?mypy=latest\u0026python=3.12\u0026gist=3daadb92c263a8447595aa7640a04599\r\n\r\n### Expected Behavior:\r\nmypy should not report any errors\r\n\r\n### Actual Behavior\r\nmypy reports an error:\r\n```\r\nItem \"None\" of \"dict[Any, Any] | None\" has no attribute \"get\"\r\n```\r\n\r\n\r\n### Environment\r\n- Mypy version used: `mypy 1.10.1 (compiled: yes)`\r\n- Mypy command-line flags: **none**\r\n- Mypy configuration options from `mypy.ini` (and other config files): **none**\r\n- Python version used: `Python 3.12.2`\r\n\r\n### Additional Details\r\n\r\nI found this issue from 2019, which seems to be the same issue: https://github.com/python/mypy/issues/6460\r\n\r\nHere people reported that it was an issue with typeshed, which was fixed in typeshed with this PR: https://github.com/python/typeshed/pull/2833\r\n\r\nI checked current trunk for typeshed and cannot spot any issue with the stubs for `max()`, the type correctly seems to indicate that the key function has nothing to do with the type of the default parameter: https://github.com/python/typeshed/blob/d482d4e83c9d247e79c87d954a9ccb11f85bfc37/stdlib/builtins.pyi#L1515-L1516\r\n\r\nSo while it seems this issue was once fixed it the past, it looks like it might have reappeared through a different cause.\r\n","author":{"url":"https://github.com/pfaion","@type":"Person","name":"pfaion"},"datePublished":"2024-07-18T08:29:52.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":3},"url":"https://github.com/17536/mypy/issues/17536"}