René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Binder fails to track loops correctly","articleBody":"```python\r\n# mypy: enable-error-code=redundant-expr\r\nfrom __future__ import annotations\r\n\r\nclass Node:\r\n    parent: Node | None\r\n    is_valid: bool\r\n\r\n    def traverse_needs_fixing(self) -\u003e Node | None:\r\n        it: Node | None\r\n        it = self\r\n        while it is not None and it.is_valid:  # E: Left operand of \"and\" is always true  [redundant-expr]\r\n            it = it.parent\r\n        return it\r\n\r\n    def traverse(self) -\u003e Node | None:\r\n        # this only works because mypy does not narrow on initial assignment\r\n        # which is something we'd like to change, see #2008\r\n        it: Node | None = self\r\n        while it is not None and it.is_valid:\r\n            it = it.parent\r\n        return it\r\n```","author":{"url":"https://github.com/hauntsaninja","@type":"Person","name":"hauntsaninja"},"datePublished":"2024-12-28T02:37:33.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/18348/mypy/issues/18348"}