On Mar 16, 1:40 pm, Peter Otten <__pete...@web.de> wrote: > mattia wrote: > > I have 2 lists, like: > > l1 = [1,2,3] > > l2 = [4,5] > > now I want to obtain a this new list: > > l = [(1,4),(1,5),(2,4),(2,5),(3,4),(3,5)] > > Then I'll have to transform the values found in the new list. > > Now, some ideas (apart from the double loop to aggregate each element of > > l1 with each element of l2): > > - I wanted to use the zip function, but the new list will not aggregate > > (3,4) and (3,5) > > - Once I've the new list, I'll apply a map function (e.g. the exp of the > > values) to speed up the process > > Some help? > > Why would you keep the intermediate list? > > With a list comprehension: > > >>> a = [1,2,3] > >>> b = [4,5] > >>> [x**y for x in a for y in b] > > [1, 1, 16, 32, 81, 243] > > With itertools: > > >>> from itertools import product, starmap > >>> from operator import pow > >>> list(starmap(pow, product(a, b))) > > [1, 1, 16, 32, 81, 243]
That looks nothing like [(1,4),(1,5),(2,4),(2,5),(3,4),(3,5)]. > > Peter -- http://mail.python.org/mailman/listinfo/python-list
