Python reverse / invert a mapping

Question

Given a dictionary like so: my_map = { 'a': 1, 'b':2 } How can one invert this map to get: inv_map = { 1: 'a', 2: 'b' } Select the correct answer from above options

Answer 1

To do reverse / invert a mapping in Python 2.7.x you can use the following piece of code:- my_map = { 'a': 1, 'b':2 } inv_map = {x: i for i, x in my_map.iteritems()} Print inv_map If you want to do reverse / invert a mapping you can use the following piece of code:- my_map = { 'a': 1, 'b':2 } inv_map = {x: i for i, x in my_map.items()} print(inv_map)