Python why would you use [:] over =

Question

I am just learning python and I am going though the tutorials on https://developers.google.com/edu/python/strings

Under the String Slices section

Answer 1

If you have a list the result is different:

l = [1,2,3]
l1 = l
l2 = l[:]

l2 is a copy of l (different object) while l1 is an alias of l which means that l1[0]=7 will modify also l, while l2[1]=7 will not modify l.