[Python-ideas] Programming recommendations (PEP 8) and boolean values

Steven D'Aprano steve at pearwood.info
Thu Aug 9 03:22:45 CEST 2012

Taking the liberty to return this to the mailing list.

On 09/08/12 08:05, Michael Foord wrote:
>> >    Why does the PEP say that == True is preferred to is True?
>>> >>
>> >
>> >  Because there surely are still libraries out there that return 0 and 1
>> >  as true/false values. The bool type was introduced in (by memory)
>> >  Python 2.2 or 2.3, so very old code may fail, or worse, silently do the
>> >  wrong thing if you use "is True".
>> >
>> >
> Surely? I haven't seen one in*years*.

Nevertheless, "return 1" is still legal Python and was once the idiomatic
way of returning a flag. If you don't have a good reason to break such old
code, why break it?


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