Matches the empty string, but only at the beginning or end of a word. A word is
defined as a sequence of alphanumeric or underscore characters, so the end of a
word is indicated by whitespace or a non-alphanumeric, non-underscore character.
- Note that ``\b`` is defined as the boundary between ``\w`` and ``\ W``, so the
+ Note that ``\b`` is defined as the boundary between ``\w`` and ``\W``, so the
precise set of characters deemed to be alphanumeric depends on the values of the
``UNICODE`` and ``LOCALE`` flags. Inside a character range, ``\b`` represents
the backspace character, for compatibility with Python's string literals.