[Python-ideas] if-statement in for-loop

[Alexander Heger]

>
> > I think wasting of indentation levels for a single logical block should
> be
> > avoided if possible to make the code more legible, otherwise one hits the
> > suggested line length limit too fast - suppose this is now inside a
> method,
> > you already lose at least 8 char ...
>
> Hence generators, which allow the nested loops to be readily factored
> out into a named operation.
>
>     def iter_interesting_triples(seq1, seq2, seq3):
>         for x in seq1:
>             if p1(x):
>                 for y in seq2:
>                     if p2(x, y):
>                         for z in seq3:
>                             if p3(x, y, z):
>                                 yield x, y, z
>
>     for x, y, z in iter_interesting_triples(seq1, seq2, seq3):
>         f(x, y, z)
>

This is an elegant solution, but I think it makes the code less clear if
one has to loop up the definition of the generator.

I any case, irrespective of limits or being dispensable, I think it would
be more consistent for the language to allow the same syntax for "for"
loops as is allowed in comprehensions.
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