Op 27/10/2021 om 11:59 schreef Chris Angelico:
You can argue the word "need" all you like, but the fact remains that
YOU want a change, so YOU have to convince people of the benefits.
That is true. But there is nothing wrong in asking what might convince
people.
But I'll give you my thought below and you can decide in how far this
is convincing to you.
I regularly come with a problem for which a one and a half loop is very
suited to solve it. Unfortunately python doesn't have a one and a half
loop. However with the introduction of the walrus operator there is a
way to simulate a significant number of one and a half loops.
Consider the following:
do
a = expr1
b = expr2
while 2 * a > b:
more calculations
We could write that now as
while [
a := expr1,
b := expr2,
2 * a > b][-1]:
more calculations
Now there is some ugly side on the above and it may not be obvious at first
what is going on, but once you understand it is a rather easy idiom. I certainly
prefer it over writing something like
while True:
a = expr1
b = expr2
if not (2 * a > b):
break
more calculations.
So for me any limitation on the walrus operator that is removed is a plus
because
it will allow me to write more one and a half loops in more natural way.
Off course should the python developers decide to intoduce a real one and a half
loop all the above is probably a whole let useful.
--
Antoon Pardon
--
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