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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Pickle ignores custom getstate methods on TextIOWrapper in Python 3.12","articleBody":"# Bug report\r\n\r\n### Bug description:\r\nSo I am not entirely sure whether this is unintended behaviour, but it is definitely a noticeable change between 3.11 and 3.12 that is rather unintuitive \r\n```python\r\nimport pickle\r\nfrom io import BytesIO, TextIOWrapper\r\n\r\nclass EncodedFile(TextIOWrapper):\r\n\tdef __getstate__(self):\r\n\t\treturn \"string\"\r\n\tdef __setstate__(self, state):\r\n\t\tpass\r\n\r\nfile = EncodedFile(BytesIO(b\"string\"))\r\npickle.dumps(file)\r\n```\r\nThis works in Python 3.11 and 3.10, but fails in 3.12 with \r\n```python\r\npickle.dumps(file)\r\nTypeError: cannot pickle 'EncodedFile' instances\r\n```\r\n\r\n\r\n### CPython versions tested on:\r\n\r\n3.10, 3.11, 3.12\r\n\r\n### Operating systems tested on:\r\n\r\nmacOS\n\n\u003c!-- gh-linked-prs --\u003e\n### Linked PRs\n* gh-122628\n* gh-133381\n\u003c!-- /gh-linked-prs --\u003e\n","author":{"url":"https://github.com/SimonSorgQC","@type":"Person","name":"SimonSorgQC"},"datePublished":"2024-08-01T12:26:59.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":6},"url":"https://github.com/122559/cpython/issues/122559"}