Python check if an item is in a list -

sorry, i'm beginner python. want see list item in. have lists set like:

    l1 = [1,2,3]       l2 = [4,5,6]       l3 = [7,8,9]   

and let's want find list item 5 in. i'm doing is:

    if l1.index(5)!=false:         print 1     elif l2.index(5)!=false:         print 2     elif l3.index(5)!=false:         print 3 

but doesn't work. how this?

you can use in operator check membership:

>>> 5 in [1, 3, 4] false >>> 5 in [1, 3, 5] true