Question about List.reverse() method

[tomliuwhite]

CountDown=[1, 2, 3]
print(CountDown.reverse())

When I run above scripts, I got the result: None instead of [3, 2, 1]
Could anyone explain to me why? Thanks.

[ndc85430]

As the documentation tells you (e.g. help(list.reverse) in the REPL), the method reverses in place (i.e. doesn't produce a new list). If you want a new value then, use reversed, but do note that it produces an iterator.