[rolux]

Yes. The following is a lot more concise:

    a = [1, 2, 3, 4]
    print([v*v for v in reversed(a) if v*v % 2 == 0])

[libria]

I think the above is a good idea of what's wrong with python (and Go), because in your example the list comp is evaluated in what seems to be this order:

    FOURTH-> print([THIRD-> v*v for v in FIRST-> reversed(a) if SECOND-> v*v % 2 == 0])

Which is all over the place. I'd rather see:

    a = [1, 2, 3, 4]
    a = reversed(a)
    a = [v*v for v in a]
    a = [w for w in a if a % 2 == 0]
    print(a)

[alfons_foobar]

This.

I often use generator expressions for the intermediate values (so I don't allocate a new list for each step), but I find this to be much more readable.