list comprehension question

[Boris Borcic]

Ross wrote:
> If I have a list of tuples a = [(1,2), (3,4), (5,6)], and I want to
> return a new list of each individual element in these tuples, I can do
> it with a nested for loop but when I try to do it using the list
> comprehension b = [j for j in i for i in a], my output is b =
> [5,5,5,6,6,6] instead of the correct b = [1,2,3,4,5,6]. What am I
> doing wrong?
> --
> http://mail.python.org/mailman/listinfo/python-list
> 

just fyi, in python 2.6

list(itertools.chain.from_iterable(a))

would do it

in python 2.5

list(itertools.chain(*a))

would do it too, but I wouldn't try it with arbitrarily long a