On Mon, 13 Oct 2014 09:56:02 +1100 Steven D'Aprano <steve+comp.lang.pyt...@pearwood.info> wrote: > > When you have multiple clauses in the condition, it's easier to reason about > them if you write the clauses as positive statements rather than negative > statements, that is, "something is true" rather than "something is not > true", and then use `not` to reverse it if you want to loop *until* the > overall condition is true. >
I was just explaining this concept to a young pup the other day. De Morgan's lets you say that (not (p and q)) == ((not p) or (not q)), but the positive logic flavor is substantially less error-prone. People are fundamentally not as good at thinking about inverted logic. -- Rob Gaddi, Highland Technology -- www.highlandtechnology.com Email address domain is currently out of order. See above to fix. -- https://mail.python.org/mailman/listinfo/python-list
