On Mon, Mar 18, 2019 at 3:42 PM Greg Ewing <greg.ew...@canterbury.ac.nz> wrote:
> Tim Delaney wrote: > > I would argue the opposite - the use of "is" shows a clear knowledge > > that True and False are each a singleton and the author explicitly > > intended to use them that way. > > I don't think you can infer that. It could equally well be someone who's > *not* familiar with Python truth rules and really just meant "if x". > Or someone who's unfamiliar with booleans in general and thinks that > every "if" statement has to have a comparison in it. > Regardless of whether it's idiomatic Python code or not, this pattern ("is True:") can be found all over Python code in the wild. If CPython ever broke this guarantee, quite a few popular libraries on pypi would be broken, including pandas, sqlalchemy, attrs and even Python's own standard library: https://github.com/python/cpython/blob/c183444f7e2640b054956474d71aae6e8d31a543/Lib/textwrap.py#L175
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