Updating a sliced list

Question

I thought I understood Python slicing operations, but when I tried to update a sliced list, I got confused:

>>> foo = [1, 2, 3, 4]
>>> foo[:1]          


        

Answer 1

Use

foo[1]  = 'two'

and

foo[2:] = ['three', 'four']

and it works.

The answer why is in the comment above (because you're using a copy)