New submission from Dan Snider <mr.assume.a...@gmail.com>:
This "bug" is present even in 2.7. I have a really hard time believing that, even if it would be incredibly rare for someone to stumble upon this, may others haven't noticed this rather glaring flaw in the code. I couldn't find any similar issues though. My idea of how conservative a standard library function should be may be skewed too far to right. So perhaps I'm mistaken that it's reasonable to assume `random.randrange(10, step=2)` should either: * raise an error warning users that providing an alternate `step` value has no effect unless `stop` is also provided; * go ahead and allow it to work. Logically, the above function call is no different than `random.randrange(0, 10, 2)`. While I have created a patch that allows alternate (positive) `step` values even if `stop` is `None`, I still think my first instinct is to say that it really should just behave like `range` by raising an error when `stop is None and step != 1`. In that way it emulates the fact `range` only takes positional arguments while keeping the performance boost the current signature has over an `*args` implementation. I'll try to attach a PR to this after posting but I've never done this before. The patch also includes a simple but effective optimization which at the very least speeds the 1 argument form by 8.5% despite the extra `step==1` check, with the only "cost" of (rightfully, imo) ensuring that only integers are used. ---------- components: Library (Lib) messages: 320717 nosy: bup priority: normal severity: normal status: open title: random.randrange completely ignores the step argument when stop is None versions: Python 3.4, Python 3.5, Python 3.6, Python 3.7 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue33998> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
