execution order in list/generator expression

[bonono at gmail.com]

Hi,

I am wondering how this is evaluated.

a=(x for x in [1,2,3,4])
p=[4,5]

c=[x for x in p if x in list(a)]

c is []

but if I expand a first, like a = list(a)

c is [4]

So it seems that the "if" part don't get expanded ?