one last one for tonight; the operator precedence summary says that "in" and "not in" has lower precedence than "is" and "is not", which has lower precedence than "<, <=, >, >=, <>, !=, ==": http://docs.python.org/ref/summary.html but the comparisions chapter http://docs.python.org/ref/comparisons.html says that they all have the same priority. which one is right ? </F>