Message242169
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 .. :) |
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Date |
User |
Action |
Args |
2015-04-28 08:53:26 | wolma | set | recipients:
+ wolma, steven.daprano |
2015-04-28 08:53:26 | wolma | set | messageid: <1430211206.61.0.689765465928.issue24068@psf.upfronthosting.co.za> |
2015-04-28 08:53:26 | wolma | link | issue24068 messages |
2015-04-28 08:53:25 | wolma | create | |
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