[New-bugs-announce] [issue24546] sequence index bug in random.choice

[Serge Anuchin]

New submission from Serge Anuchin:

It seems there is minor bug in random.choice.

I've got traceback from my server with IndexError from random.choice, but sequence wasn't empty (seq value was: u'\u0411\u0413\u0414\u0416\u0418\u041b\u0426\u042b\u042d\
u042e\u042f\u0410\u0412\u0415\u041a\u041c\u0420\u0422\
u042312456789')

Maybe I mistaken, but only explanation that I have for this exception is rounding by int() of random value that was very close to 1.

TL;RD:
>>> int(0.99999999999999995)
1
>>> seq = 'test'
>>> seq[int(0.99999999999999995 * len(seq))] # logic from random.choice
IndexError: string index out of range

Is it plausible explanation of exception or I'am wrong?

----------
components: Library (Lib)
messages: 246038
nosy: Serge Anuchin, mark.dickinson, rhettinger
priority: normal
severity: normal
status: open
title: sequence index bug in random.choice
type: behavior
versions: Python 2.7

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue24546>
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