While trying to learn a little more about regular expressions, a tutorial suggested that you can use the `\b` to match a word boundary. However, the following snippet in the Python interpreter does not work as expected:

```
>>> x = 'one two three'
>>> y = re.search("\btwo\b", x)

```

It should have been a match object if anything was matched, but it is `None`.

Is the `\b` expression not supported in Python or am I using it wrong?