Class FollowedBy

source code

     object --+        
              |        
  ParserElement --+    
                  |    
ParseElementEnhance --+
                      |
                     FollowedBy

Lookahead matching of the given parse expression. ``FollowedBy`` does *not* advance the parsing position within the input string, it only verifies that the specified parse expression matches at the current position. ``FollowedBy`` always returns a null token list. If any results names are defined in the lookahead expression, those *will* be returned for access by name.

Example:

   # use FollowedBy to match a label only if it is followed by a ':'
   data_word = Word(alphas)
   label = data_word + FollowedBy(':')
   attr_expr = Group(label + Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join))

   OneOrMore(attr_expr).parseString("shape: SQUARE color: BLACK posn: upper left").pprint()

prints:

   [['shape', 'SQUARE'], ['color', 'BLACK'], ['posn', 'upper left']]