Steven Bethard wrote: > It's me wrote: >> Say again??? > > Please stop top-posting -- it makes it hard to reply in context. > >> "Reinhold Birkenfeld" wrote... >>>It's me wrote: >>>>If this is true, I would run into trouble real quick if I do a: >>>> >>>>(1/x,1.0e99)[x==0] >>> >>>Lazy evaluation: use the (x==0 and 1e99 or 1/x) form! > > If you want short-circuting behavior, where only one of the two branches > gets executed, you should use Python's short-circuiting boolean > operators. For example, > > (x == 0 and 1.0e99 or 1/x) > > says something like: > > Check if x == 0. > If so, check if 1.0e99 is non-zero. It is, so return it. > If x != 0, see if 1/x is non-zero. It is, so return it. > > Note that if you're not comfortable with short-circuiting behavior, you > can also code this using lazy evaluation: > > (lambda: 1/x, lambda: 1.0e99)[x==0]()
Or even (x==0 and lambda: 1e99 or lambda: 1/x)() Or ... Reinhold -- http://mail.python.org/mailman/listinfo/python-list
