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From: Cameron Simpson <cs@zip.com.au>
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Subject: Re: I'm missing something here...
Date: Tue, 12 Jan 2016 18:13:22 +1100
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On 11Jan2016 23:55, Erik <python@lucidity.plus.com> wrote:
>On 11/01/16 23:26, Skip Montanaro wrote:
>>If I change the last line of find_problems to call
>>prob_dates.update(), the message disappears. Why is pylint (1.4.2 BTW)
>>complaining that the prob_dates argument of find_problems is unused
>>when I use the |= operator?
>
>Is it complaining about that, or is it because the 'for' loop body might be 
>executed zero times?

The former. Almost any loop _might_ be executed zero times. Compilers and 
linters etc should only complain if they can prove the loop is always executed 
zero times.

Cheers,
Cameron Simpson <cs@zip.com.au>