How Can I Invert a Dictionary's Key-Value Pairs in Python?

Inverting a Dictionary Mapping

Given a dictionary with key-value pairs, such as:

my_map = {'a': 1, 'b': 2}

The goal is to create an inverted dictionary where the values become keys and the keys become values:

inv_map = {1: 'a', 2: 'b'}

Solution

In Python 3 and above, this can be achieved using a dictionary comprehension:

inv_map = {v: k for k, v in my_map.items()}

Here, the items() method returns a list of key-value tuples, and the dictionary comprehension iterates over these tuples to create a new dictionary with inverted keys and values.

For Python 2, the iteritems() method can be used instead:

inv_map = {v: k for k, v in my_map.iteritems()}

The above is the detailed content of How Can I Invert a Dictionary's Key-Value Pairs in Python?. For more information, please follow other related articles on the PHP Chinese website!