[Python-Dev] for...else (original) (raw)

Rob Cliffe rob.cliffe at btinternet.com
Tue Jul 25 06:28:38 EDT 2017

On 25/07/2017 06:51, Nick Coghlan wrote:

On 25 July 2017 at 02:23, Ben Hoyt <benhoyt at gmail.com> wrote:

This is more of a python-ideas discussion, and Steven's answer is good.

I'll just add one thing. Maybe it's obvious to others, but I've liked for...else since I found a kind of mnemonic to help me remember when the "else" part happens: I think of it not as "for ... else" but as "break ... else" -- saying it this way makes it clear to me that the break goes with the else. "If this condition inside the loop is true, break. ... else if we didn't break, do this other thing after the loop." For folks looking for a more in-depth explanation of the "if-break-else" approach to thinking about this construct: http://python-notes.curiousefficiency.org/en/latest/pythonconcepts/breakelse.html A helpful explanation. But that it is necessary at all underlines that (IMHO) this use of 'else' is unnatural and hard to understand. I always have to think twice about it, whether reading it or using it myself. Therefore I would have preferred a more obvious keyword such as 'ifnobreak' (others may think of something better). But as has been stated, it's not going to change. Rob Cliffe

That article also has a note explaining that we're unlikely to ever change this: http://python-notes.curiousefficiency.org/en/latest/pythonconcepts/breakelse.html#but-couldn-t-python-be-different Cheers, Nick.

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