Removing from a List in Place

John Machin sjmachin at lexicon.net
Wed Sep 6 01:29:11 CEST 2006


bayerj wrote:
> > I'm going to assume that it's supposed to work like this, but could
> > someone tell me the reasoning behind it?  I.E. why is 3 skipped?
>
> Because:
>
> >>> alist[2]
> 3
>
> You are removing the third item, not the second.

This is incorrect.
You may need to remind yourself that the arg of remove is a value to be
searched for and then removed, not an index. del alist[2] would remove
the third item.

You may have been confused by the OP's obfuscatory example alist = [1,
2, 3].
Consider this equivalent:
| >>> alist = ['foo', 'bar', 'zot']
| >>> for item in alist:
| ...     print item
| ...     if item == 'bar':
| ...         alist.remove(item)
| ...
| foo
| bar
| >>> alist
| ['foo', 'zot']
| >>>

HTH,
John




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