Due to the way 'and' and 'or' work you can do C?E1:E2 as:
((C and E1) or E2)
Guido'll have to say whether this is an accidental hack or Official
Python Idiom, however.
---- Jack Jansen | If I can't dance I don't want to be part of Jack.Jansen@cwi.nl | your revolution -- Emma Goldman uunet!cwi.nl!jack G=Jack;S=Jansen;O=cwi;PRMD=surf;ADMD=400net;C=nl