--- a/python/yacc.py	Fri Mar 21 10:27:57 2014 +0100
+++ b/python/yacc.py	Fri Mar 21 11:21:50 2014 +0100
@@ -102,11 +102,13 @@
                 if section == 0:
                     if line.startswith('%tokens'):
                         yield('%tokens', '%tokens')
-                        yield from tokenize_line(line[7:])
+                        for tk in tokenize_line(line[7:]):
+                            yield tk
                     else:
                         yield ('HEADER', line)
                 elif section == 1:
-                    yield from tokenize_line(line)
+                    for tk in tokenize_line(line):
+                        yield tk
             yield ('eof', 'eof')
         self.tokens = tokenize()
         self.token = self.tokens.__next__()