Feature or enhancement

In Python 3.13 alpha1, I removed the private _PyLong_NumBits() function. It seems like this function is used by pywin32 and MariaDB projects: see issue gh-119336.

I propose to add a public function to replace it:

Py_ssize_t _PyLong_GetNumBits(PyObject *obj);

• Return the number of bits on success: greater than or equal to zero.
• Set an exception and return -1 on error.
• Set an OverflowError exception, and return -1 if the number of bits doesn't fit into Py_ssize_t.

The C function is similar to the Python int.bit_length() method.

See also the proposed PyLong_GetSign() function.

Linked PRs

• gh-119714: Add PyLong_GetNumBits() function #119715