Re: [Python-ideas] Accessing the result of comprehension's expressionfrom the conditional

[Lie Ryan]

In list/generator comprehension, currently we have no way to access the result of the expression and have to write something like this:

[f(x) for x in l if f(x) > 0]

if f() is heavy or non-pure (i.e. have side effects), calling f() twice might be undesirable.

[x for x in map(f, l) if x > 0] Raymond