René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Update FileIO comments, documentation to match implementation","articleBody":"# Documentation\n\nDiscuss thread: https://discuss.python.org/t/change-open-write-to-guarantee-all-bytes-will-be-written-or-an-exception-will-be-thrown/71082\n\n1. FileIO behaves differently than its code comments around `read` and `readall`. Update the code comments to match current behavior\n   - [PEP 475](https://peps.python.org/pep-0475/), reads are retried in some cases\n   - `.readall()` makes multiple system calls by design\n3. Add documentation to [`open()` builtin](https://docs.python.org/3.14/library/functions.html#open) that `buffering=0`, which currently just says \"disables buffering\") changes how `.write()` behaves and may result in data loss as a result of a partial write (ex. gh-126606).\n   - `TextIO` and `BufferedIO` (which are gotten via commonly used `open('README.rst')`, `open('README.rst', 'rb')`) retry partial writes providing a user a guarantee either all bytes will be written or an exception will be thrown.\n   - `FileIO` is \"Raw I/O\" and by [PEP-3116](https://peps.python.org/pep-3116/#raw-i-o) design, as documented, and currently implemented does not retry partial writes. \n   - Most the time, `buffering=0` currently speeds up writing a file, but it can also result in corrupted files, ex. gh-126606 from using FileIO directly\n   - I would like to try and change the behavior of `buffering=0` to use BufferedIO but with a 0 sized buffer, and that is on my roadmap but will be a while (people use the flag for a reason / get benefit!). This will mean `open()` always returns an object which implements \"Write all or throw exception\" behavior.\n   - Add warning / document existing behavior on `open()` in the meantime.\n\n\u003c!-- gh-linked-prs --\u003e\n### Linked PRs\n* gh-129012\n* gh-135328\n* gh-150957\n* gh-150958\n* gh-150959\n\u003c!-- /gh-linked-prs --\u003e\n","author":{"url":"https://github.com/cmaloney","@type":"Person","name":"cmaloney"},"datePublished":"2025-01-19T01:19:28.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/129011/cpython/issues/129011"}