New assignmens ...

Antoon Pardon antoon.pardon at
Thu Oct 28 04:04:11 EDT 2021

Op 27/10/2021 om 17:05 schreef Christman, Roger Graydon:
> I'm going to provide two loop-and-a-half segments to illustrate my interpretation
> of this PEP and the purpose of the walrus operator:
> [ first example ]
> Now contrast with this example:
> Without the walrus:
> replay = True
> while replay:
>      play_game()
>      replay = input("Play again? ") in ['y','Y','yes','Yes']
> (I think it silly to ask about playing again at first).
> With the walrus:
> replay = None
> while replay==None or (replay := input("Play again? ") in ['y','Y','yes','Yes']:
>       play_game()
> To use the walrus operator here, I have to fabricate a value that would
> allow me to bypass the input operation, that cannot be otherwise produced.
> I do not find this second version any clearer or more intuitive than the first
> (and the PEP did emphasize the value of clarity).

But the above is not a one and a half loop. The above is essentially a do
loop (repeat loop in pascal), where you have the test at the end of the
loop body. But because python doesn't have that loop you have to use a
boolean to control the loop that is initialized to True and then later
assign that boolean the result of the test which you use to control this

Should I think it worth the trouble to rewrite your example, quod non,
it would be like below, with that unneeded list.

     while [
     input("Play again? ") in ['y', 'Y', 'yes', 'Yes']][-1]:

Antoon Pardon.

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