Raymond Hettinger <raymond.hettin...@gmail.com> added the comment:
Donovan, if the speed of the power of two case is important to you, I recommend using getrandbits() instead. It is ten times faster. $ python3.9 -m timeit -r 11 -s 'from random import randrange, getrandbits' 'randrange(2**32)' 1000000 loops, best of 11: 362 nsec per loop $ python3.9 -m timeit -r 11 -s 'from random import randrange, getrandbits' 'getrandbits(32)' 10000000 loops, best of 11: 32 nsec per loop The two referenced articles aren't pertinent to this issue, the power of two case for randrange(). Both articles boil down to finding that a single task, arity zero, C coded method is significantly faster than a pure python method with error checking, a complex signature, support for arbitrarily large integers, and extra effort to assure an equal distribution. It is unsurprising random() is faster than randrange(). Code that does less work is faster than code that does more work. Mark is correct that the current code wasn't an accident and that we intensionally chose to keep reproducibility. I appreciate your suggestion, but it essentially same one that was rejected in bpo-37000. As Mark pointed out, nothing has changed since then (though some other changes have been added to 3.10 that improved the speed of rangerange() without affecting reproducibility). Note, even if the PR had been accepted, you would still be much better off with getrandbits(). ---------- resolution: -> duplicate stage: patch review -> resolved status: open -> closed superseder: -> _randbelow_with_getrandbits function inefficient with powers of two _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue43040> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
