On Sep 8, 9:32 am, Bruno Desthuilliers <[EMAIL PROTECTED]> wrote: > mathieu a écrit : > > > Hi there, > > > I am trying to write something very simple to test if a list > > contains another one: > > > a = [1,2,3] > > > b = [3,2,1,4] > > > but 'a in b' returns False. > > Indeed. Lists are not sets, and the fact that all elements of list a > happens to also be part of list b doesn't make the list a itself an > element of list b. > > >>> a = [1, 2, 3] > >>> b = [3,2,1,4] > >>> c = [b, a] > >>> a in c > True > >>> b in c > True > >>> c > [[3, 2, 1, 4], [1, 2, 3]] > >>> > > > How do I check that a is indeed contained > > in b ? > > But that's what you did - you *did* checked if a was contained in b, and > this is not the case. What you want is to check if *all elements* of a > are contained in b, which is quite another problem. Now the answer to > your question : use sets. > > >>> set(a).issubset(set(b)) > True > >>>
thanks all ! -- http://mail.python.org/mailman/listinfo/python-list
