On Sat, Aug 6, 2011 at 6:07 PM, smith jack <thinke...@gmail.com> wrote: > if a list L is composed with tuple consists of two elements, that is > L = [(a1, b1), (a2, b2) ... (an, bn)] > > is there any simple way to divide this list into two separate lists , such > that > L1 = [a1, a2... an] > L2=[b1,b2 ... bn] > > i do not want to use loop, any methods to make this done?
One easy way is to use list comprehensions. Technically that'll involve a loop, but the loop is handled efficiently under the hood. L1 = [x[0] for x in L] L2 = [x[1] for x in L] Another way would be to construct a dictionary from your list of tuples and then use the keys() and values() of that dictionary to form your lists (use collections.OrderedDict if the order matters). But I think the list comps are the best way. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
