How to split long regular expression rules to multiple lines in Python

You can split your regex pattern by quoting each segment. No backslashes needed.

test = re.compile(('(?P<full_path>.+):\d+:\s+warning:\s+Member'
                   '\s+(?P<member_name>.+)\s+\((?P<member_type>%s)\) '
                   'of (class|group|namespace)\s+(?P<class_name>.+)'
                   '\s+is not documented') % (self.__MEMBER_TYPES), re.IGNORECASE)

You can also use the raw string flag 'r' and you’ll have to put it before each segment.

See the docs.