def _is_robot():
robot_regex = current_app.config['<STR_LIT>']<EOL>user_agent = request.headers.get('<STR_LIT>', '<STR_LIT>')<EOL>return re.search(robot_regex, user_agent, flags=re.VERBOSE)<EOL>
Return `True` if the current visitor is a robot or spider, or
`False` otherwise.

This function works by comparing the request's user agent with a regular
expression.  The regular expression can be configured with the
``SPLIT_ROBOT_REGEX`` setting.