[Python-Dev] comprehension abbreviation (was: Adding any() and all())

Eric Nieuwland eric.nieuwland at xs4all.nl
Tue Mar 15 22:46:36 CET 2005

Martin v. Löwis wrote:
> That's not the full syntax. The full syntax is
>     [ <test> for <exprlist> in <testlist> <list-iter-opt> ]
> where
> <test> can be an arbitrary expression: and, or, lambda, +, -, ...
> <exprlist> can be a list of expression, except for boolean and
> relational expressions (but I think this is further constrained
> semantically)
> <testlist> list a list of tests
> <list-iter-opt> is optional, and can be another for or if block

Aren't these names a bit mixed up w.r.t. what's in that position? As 
far as I know
<test> is not a test but a function as it produces any value not just 
<exprlst> is a list of names, not arbitrary expressions
<testlist> is anything which will produce an iterator

Or so I've understood so far.

> So a more complex example is
>    [ lambda a: a[x]+y*z for x,y in A for z in B if x > z]
I'm schocked ;-)


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