On Fri, 01 May 2009 01:56:50 -0700, Paul Rubin wrote: > Steven D'Aprano <st...@remove-this-cybersource.com.au> writes: >> (2) Why assume that a, b and c are sequences with a fast __len__ >> method? They might be (say) linked lists that take O(N) to calculate >> the length, or binary trees that don't even have a length, but can be >> iterated over. > > Why assume they have a bool method? Or a __or__ operator?
What programming language are you using? I'm using Python, where objects don't require either a bool or __or__ method (not operator) to work with the or operator. >>> hasattr(None, '__or__') or hasattr(None, '__bool__') or \ ... hasattr(None, '__nonzero__') False >>> >>> x = object() >>> hasattr(x, '__or__') or hasattr(x, '__bool__') or \ ... hasattr(x, '__nonzero__') False >>> >>> None or x <object object at 0xb7f3b4f0> Any object can be used as an operand to the boolean operators. > Eh. > > for seq in [a,b,c]: > if sum(1 for x in imap(do_something_with, seq)) > 0: > break Did I stumble into an Obfuscated Python competition? -- Steven -- http://mail.python.org/mailman/listinfo/python-list
