How do I reverse a part (slice) of a list in Python?

Question

Why doesn\'t this work?

# to reverse a part of the string in place 
a = [1,2,3,4,5]
a[2:4] = reversed(a[2:4])  # This works!
a[2:4] = [0,0]             # Thi         


        

Answer 1

a[2:4] is a copy of the list a that is built using the 2,3,4 items in list a. The first two work because you are assigning the changes into those spots in the original list. The last one doesn't work because you are not affecting the original list.