python - Swapping first and last items in a list

Question

How can I go about swapping numbers in a given list?

For example:

list = [5,6,7,10,11,12]

I would like to swap 12 with 5.

Is there an built-in Python function that can allow me to do that?

Answer 1

>>> lis = [5,6,7,10,11,12]
>>> lis[0], lis[-1] = lis[-1], lis[0]
>>> lis
[12, 6, 7, 10, 11, 5]

Order of evaluation of the above expression:

expr3, expr4 = expr1, expr2

First items on RHS are collected in a tuple, and then that tuple is unpacked and assigned to the items on the LHS.

>>> lis = [5,6,7,10,11,12]
>>> tup = lis[-1], lis[0]
>>> tup
(12, 5)
>>> lis[0], lis[-1] = tup
>>> lis
[12, 6, 7, 10, 11, 5]