As mentioned somewhere, "readability counts", so why not just go with exactly
what you said...
if len(nominees) > 0: #if a condition exists
for nominee in nominees: #the loop should be executed
print(nominee)
else: #but if not
print("D'oh! No one is worthy.") #something else should be done
The fancy features of the language can be cool and all, but forcing yourself to
use them just for the sake of using them and "being pythonic" can result in
weird situations, and wrong or unclear assumptions or intents. When someone
else reads it later it may hide what you were actually intending the check to
look for.
Hmm, "if nominees:" Did they make it like that to look for a 0 length list, or
to make sure they didn't get None by accident, or both, or something different?
Hmm, "if len(nominees) > 0:" Ahh ok, we want to make sure there's something in
there.
So my 2 cents: Feel free to be non-pythonic if it makes things clear and works.
-----Original Message-----
From: Python-list
[mailto:python-list-bounces+david.raymond=tomtom....@python.org] On Behalf Of
Peter Otten
Sent: Tuesday, February 05, 2019 3:44 AM
To: python-list@python.org
Subject: Re: Loop with else clause
DL Neil wrote:
> What is the pythonic way to handle the situation where if a condition
> exists the loop should be executed, but if it does not something else
> should be done?
> Possible solution:
> To make anything more than the trivial case readable, I think I'd put
> the list processing into one function, and the exception into another
> (except that this case is so trivial), ie
>
> if list:
> process_list() #the heading and for-loop, as above
> else:
> print( "Sorry...
>
>
> Others wanted to add a semaphore/flag inside the loop to indicate if it
> was executed at least once. Yes, could even use the else clause then!
An argument in favour of the flag is that it works with arbitrary iterables
whereas if ...: fails:
>>> numbered = enumerate([])
>>> if numbered:
... print("the winners are")
... for ix in numbered: print(*ix)
...
the winners are
> The ideas went (rapidly) down-hill from there...
>
>
> Is there another, more pythonic, approach to conditional (for/while)
> loop processing?
I'm not aware of such an approach.
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