René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Calling help() on a dataclass shows dataclass internal names instead of type names in 3.14 or later","articleBody":"# Bug report\n\n### Bug description:\n\nIf you call `help` on a dataclass in Python 3.14 or later it shows the internal type names used for the exec call in the signature.\n\nDocstring included to hide the dataclasses generated `__doc__` which would just confuse things.\n\n```python\nfrom dataclasses import dataclass\n\n@dataclass\nclass Example:\n    \"docstring\"\n    x: int\n\nhelp(Example)\n```\n\nBefore, on 3.13\n```\nHelp on class Example in module __main__:\n\nclass Example(builtins.object)\n |  Example(x: int) -\u003e None\n |\n |  docstring\n |\n |  Methods defined here:\n |\n |  __eq__(self, other)\n |      Return self==value.\n |\n |  __init__(self, x: int) -\u003e None\n |      Initialize self.  See help(type(self)) for accurate signature.\n...\n```\n\nNow, on 3.14 or later\n```\nHelp on class Example in module __main__:\n\nclass Example(builtins.object)\n |  Example(x: __dataclass_type_x__) -\u003e __dataclass___init___return_type__\n |\n |  docstring\n |\n |  Methods defined here:\n |\n |  __eq__(self, other)\n |      Return self==value.\n |\n |  __init__(self, x: __dataclass_type_x__) -\u003e __dataclass___init___return_type__\n |      Initialize self.  See help(type(self)) for accurate signature.\n...\n```\n\nThis looks a bit messy and reveals inner details that users of `help` probably don't need to see.\n\nIt looks like this comes from `inspect.signature(cls, annotation_format=Format.STRING)` being used in pydoc, but I think it's a dataclasses issue.\n\n`attrs` doesn't suffer the same fate as it attaches annotations as `__annotations__` instead of defining them in the source code string to be evaluated.\n\nInspired by that, for my own dataclass-like implementation for 3.14+ I'm collecting the annotations and generating an `__annotate__` function which appears to solve this issue: [see here](https://github.com/DavidCEllis/ducktools-classbuilder/blob/57b6e651fdd8766a7d76f8ade82b2e0a41756c17/src/ducktools/classbuilder/annotations.py#L86-L113)\n\n`dataclasses` could potentially do something similar. \n\n### CPython versions tested on:\n\n3.14, CPython main branch\n\n### Operating systems tested on:\n\n_No response_\n\n\u003c!-- gh-linked-prs --\u003e\n### Linked PRs\n* gh-137711\n* gh-141352\n\u003c!-- /gh-linked-prs --\u003e\n","author":{"url":"https://github.com/DavidCEllis","@type":"Person","name":"DavidCEllis"},"datePublished":"2025-08-07T19:35:17.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":11},"url":"https://github.com/137530/cpython/issues/137530"}