Swapping values

Question

I have seen this code used to swap the values of two variables -

a, b = b, a

How does this work?

Answer 1

a,b = b,a

Here, python interprets the comma separated variables as tuples. The RHS is first evaluated as a tuple and then stored in memory. The LHS is then evaluated as a tuple and is assigned the values of the RHS. Hence, the net effect is that the values of the variables are swapped.