Reverse / invert a dictionary 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'} ```

Accepted Answer

Python 3+:

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

Python 2:

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

Solution