On Mar 7, 7:14 pm, "Sergio Correia" <[EMAIL PROTECTED]> wrote: > Hi, > > I'm looking for an easy way to flatten a two level list like this > > spam = [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10, 11, 12]] > > Into something like > eggs = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12] > > There are *no* special cases (no empty sub-lists). > > I have found two ways: > > 1) Accumulator > eggs = [] > for x in eggs: > eggs.extend(x) > > 2) Reduce > eggs = reduce(lambda x, y: x+y, spam) > > I feel the 1st way is too cumbersome (three lines), and although I > like the 2nd way (except for the lambda part), I understand reduce is > discouraged by Guido so I want to know if there is a "Better Way"(TM) > ? > > Any ideas? > > Thanks, > Sergio > > PS: Why does `sum` works only with numbers?
A search in the python group should get you all the details you need. Quick answer: "sum(eggs, [])", but the "correct" way is to have a flatten() function, with those 3 lines. -- http://mail.python.org/mailman/listinfo/python-list
