Switching Two Values in Dictionary, Keeping Keys Constant

Question

What would be the most efficient way to switch say two values in a dictionary, so that two keys would be mapping to two different values?

Answer 1

Use tuple assignment:

d['bar'], d['foo'] = d['foo'], d['bar']

This simply swaps the values. The Python compiler optimizes for such cases, and this doesn't require any frame stack pushes (provided d doesn't implement __getitem__ and / or __setitem__ hooks in Python code).

Answer 2

The same way you would swap any other values:

my_dict[key0], my_dict[key1] = my_dict[key1], my_dict[key0]