New submission from anon: For many numeric algorithms it's useful to be able to read individual bits at a location in an integer. Currently there is no efficient way to do this. The following function is the closest to this:
def bit_at(i, n): return (i>>n)&1 However in computing the intermediate result i>>n we must spend O(b-n) time at least (where b is n.bit_length()). It should be possible to read bits in O(1) time. Adding int.bit_at(n) would complement int.bit_length(). I would suggest making the semantics of i.bit_at(n) the same as (i>>n)&1. Although the exact meaning when i is negative should be considered. Real world uses of bit_at include binary exponentiation and bit counting algorithms. ---------- messages: 205421 nosy: anon priority: normal severity: normal status: open title: int.bit_at(n) - Accessing a single bit in O(1) type: enhancement versions: Python 3.5 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue19915> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
