On Sat, 5 Mar 2022 at 03:44, Avi Gross via Python-list
<python-list@python.org> wrote:
>
> Dieter,
>
> Your use is creative albeit it is not "needed" since all it does is make sure
> your variable is initialized to something, specifically None.
>
> So would this not do the same thing?
>
> eye = None
>
> for eye in range(0):
> print(eye)
>
> eye
>
> If I understand it, your example depends on a variable that is not yet
> initialized to be used in a loop and retain the last value after the loop.
> You then set it to None if it is not used as the loop is skipped. Others have
> shown an example similar to the above of using a sentinel that lets you know
> if the loop is skipped.
>
> Of course, there are some advantages in making it clear by doing it you way
> that the loop (for example if copied and used elsewhere) needs to include the
> else statement as an integral part.
>
> I would like to suggest a slight modification to the above as in if you are
> searching for something in either seq1 and if not found in seq2. Call it
> looking for your green shirt in the closet and if not found, looking in the
> attic. Would this code make sense as such a use in several ways? In English,
> look here first and if there is NOTHING there, look in the second place?
>
> closet = []
>
> attic = ["Costumes", "Sheets", "Shirts" ]
>
> for item in closet:
> print(item)
> if item == "Shirts" : print("FOUND in closet!!")
> else:
> for item in attic:
> print(item)
> if item == "Shirts" : print("FOUND in attic!!")
>
> Yes, as discussed, you could do an IF statement to check if closet is empty
> but for iterators, it gets ...
>
Make sure you 'break' after finding it. Otherwise, you'll keep
searching the rest of your closet, and then still go on to search your
attic. The "else:" clause doesn't help you here unless that break is
present.
ChrisA
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