deleting elements from a list in a for loop

flupke flupke at nonexistingdomain.com
Fri Oct 29 16:54:04 CEST 2004


Benjamin Niemann wrote:
> If it doesn't matter in which order you scan the list:
> 
> for idx in xrange(len(el), -1, -1):
>     element = el[idx]
>     if ....:
>         del el[idx]
> 
> By running from end to start of the list, a "del" won't affect later 
> iterations of the loop.
> Generally: you shouldn't modify a list while doing a "for a in el:" - 
> this just causes confusion (as you've already seen ;)

Scan order doesn't matter so i could also use this sollution.
The for line should be "for idx in xrange(len(el)-1, -1, -1):"
for it to work.

Any, also a great sollution, thanks!

Benedict



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