New submission from Ned Batchelder: Creating two Random() instances in quick succession produces the same sequence, but only on Windows on Python 3.6. On 3.5 or earlier, or on Mac/Linux, the randomization is good.
Python 3.6.0 (v3.6.0:41df79263a11, Dec 23 2016, 07:18:10) [MSC v.1900 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> import random; print(random.Random().randint(1, 999999), >>> random.Random().randint(1, 999999)) 903885 903885 >>> import random; print(*[random.Random().randint(1, 999999) for _ in >>> range(2)]) 996947 56476 >>> import random; print(*[random.Random().randint(1, 999999) for _ in >>> range(2)]) 793282 793282 >>> import random; print(*[random.Random().randint(1, 999999) for _ in >>> range(2)]) 519702 519702 >>> import random; print(*[random.Random().randint(1, 999999) for _ in >>> range(2)]) 230678 230678 >>> import random; print(*[random.Random().randint(1, 999999) for _ in >>> range(3)]) 474701 474701 474701 >>> import random; print(*[random.Random().randint(1, 999999) for _ in >>> range(3)]) 890942 890942 890942 >>> import random; print(*[random.Random().randint(1, 999999) for _ in >>> range(3)]) 997495 997495 997495 >>> import random; print(*[random.Random().randint(1, 999999) for _ in >>> range(5)]) 27803 27803 27803 27803 919401 >>> I would expect each of these runs to produce unique numbers, with no duplicates. ---------- keywords: 3.6regression messages: 284118 nosy: nedbat priority: normal severity: normal status: open title: Python 3.6 on Windows doesn't seed Random() well enough _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue29085> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com