[Python-ideas] for/else syntax
Stephen J. Turnbull
stephen at xemacs.org
Thu Oct 1 15:37:09 CEST 2009
Antti Rasinen writes:
> never used it. Three uninitiated, in other words.
Well, of course it's unintuitive, then. In practical programming,
"unintuitive" is synonymous with "I've never used it in a real
> Here are their reactions, when they learned how it really works:
> * "It should be called for..then" (or for..finally)
I don't know about the semantics I'd guess for "then", but I think I'd
consider that synonymous with "finally". IMO it's non-starter anyway
because it's not already a keyword; this pattern is a little too
uncommon to justify a new keyword. "finally" is no good because in
try blocks it means "no matter what, do this". Having slightly
different semantics in try blocks and loops would be a real loser.
> To add further insult to the naming injury, the else branch suffers from
> the fact that 99.9% of the time, the for-loop contains an if:
> for x in xs:
> if cond(x):
> # stuff
> # more stuff
> My code pattern matching algorithm reads that as an indentation error. An
> else matches if so many times more often that decoding for..else requires
> unnecessary effort.
I guess. However, you're a native speaker of a natural language, so I
bet you can deal with idioms that are *much* less intuitive than this
one, if used in context. Probably even in English (which I guess is
not your native language). I find the search idiom very natural,
almost intuitive (even though I've never used it myself<wink>), now
that I've seen it in Nick's post. Don't you?
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