[Python-Dev] Examples for PEP 572
storchaka at gmail.com
Wed Jul 4 03:58:48 EDT 2018
04.07.18 05:42, Steven D'Aprano пише:
> On Tue, Jul 03, 2018 at 09:54:22PM -0400, Terry Reedy wrote:
>>> results = [(x, y, x/y) for x in input_data for y in [f(x)] if y > 0]
>> Would (f(x),) be faster?
> There is a deferred feature request to optimize "for x in [item]" as
> equivalent to "for x in (item,)", to avoid constructing a list:
No, this optimization was already made in issue32925. Issue32856 is a
different optimization -- it makes such constructions be as fast as a
simple assignment. It allows to use an assignment in comprehensions
without introducing a new syntax and with zero overhead.
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