René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Deprecate Py_HASH_EXTERNAL as it cannot be used for `--with-hash-algorithm`","articleBody":"# Bug report\n\n### Bug description:\n\nIn PEP-456, we introduced the notion of interchangeable hash functions for strings, bytes and memoryviews. Historically, Python used FNV as its hash algorithm, switched to SipHash2-4 in 3.4 before making SipHash1-3 the default in 3.11. It is however possible for embedders to implement their own hashing algorithms but this requires Python to be configured with `--with-hash-algorithm=external` and linking Python with the appropriate additional library.\n\nUnfortunately, it's not possible to choose `external` and the only workaround would be to pass `-DPy_HASH_ALGORITHM 0` but this is neither documented nor tested (it may not even work if the macro is still defined afterwards).\n\n### CPython versions tested on:\n\nCPython main branch\n\n### Operating systems tested on:\n\n_No response_\n\n\u003c!-- gh-linked-prs --\u003e\n### Linked PRs\n* gh-141245\n* gh-141287\n\u003c!-- /gh-linked-prs --\u003e\n","author":{"url":"https://github.com/picnixz","@type":"Person","name":"picnixz"},"datePublished":"2025-11-08T09:20:01.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":8},"url":"https://github.com/141226/cpython/issues/141226"}