New submission from Wolfgang Maier: the mean function in the statistics module gives nonsensical results with boolean values in the input, e.g.:
>>> mean([True, True, False, False]) 0.25 >>> mean([True, 1027]) 0.5 This is an issue with the module's internal _sum function that mean relies on. Other functions relying on _sum are affected more subtly, e.g.: >>> variance([1, 1027, 0]) 351234.3333333333 >>> variance([True, 1027, 0]) 351234.3333333334 The problem with _sum is that it will try to coerce its result to any non-int type found in the input (so bool in the examples), but bool(1028) is just True so information gets lost. I've attached a patch preventing the type cast when it would be to bool. I don't have time to write a separate test though so if somebody wants to take over .. :) ---------- components: Library (Lib) files: statistics._sum.patch keywords: patch messages: 242169 nosy: steven.daprano, wolma priority: normal severity: normal status: open title: statistics module - incorrect results with boolean input type: behavior versions: Python 3.4, Python 3.5 Added file: http://bugs.python.org/file39220/statistics._sum.patch _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue24068> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
