C API: Consider adding public PyLong_AsByteArray() and PyLong_FromByteArray() functions #111140
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URL: https://github.com/python/cpython/issues/111140
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Feature or enhancement
The private
_PyLong_AsByteArray()and_PyLong_FromByteArray()functions were removed in Python 3.13: see PR #108429.@scoder asked what is the intended replacement for
_PyLong_FromByteArray().The replacement for
_PyLong_FromByteArray()isPyObject_CallMethod((PyObject*)&PyList_Type, "from_bytes", "s#s", str, len, "big")but I'm not sure what is the easy way to set the signed parameter to True (default:signed=False).The replacement for
_PyLong_AsByteArray()isPyObject_CallMethod(my_int, "to_bytes", "ns", length, "big"). Same, I'm not sure how to easy set the signed parameter to True (default:signed=False).I propose to add public PyLong_AsByteArray() and PyLong_FromByteArray() functions to the C API.
Python 3.12 modified PyLongObject: it's no longer a simple array of digits, but it's now a more less straightforward
_PyLongValuestructure which requires using unstable functions to access small "compact" values:So having a reliable and simple way to import/export a Python int object as bytes became even more important.
A code search for
_PyLong_AsByteArrayin PyPI top 5,000 projects found 12 projects using it:Linked PRs