On Tue, 13 Dec 2005 09:46:30 +0000, Steve Holden wrote: > Paul Rubin wrote: >> Steve Holden <[EMAIL PROTECTED]> writes: >> >>>The really interesting question your post raises, though, is "Why do >>>you feel it's necessary to test to see whether a variable is a >>>Boolean?". >> >> >> What's the point of having Booleans, if you can't tell them from integers? > > Booleans are specifically defined as a subtype of int at the C level.
That's an implementation detail, and in fact an explicit decision made, not a inescapable fact of programming. What you are saying is, effectively, the point of having bools which are subclasses of ints is that Guido wanted them that way. > One might also ask "what's the point of having floats if you can't tell > them from integers": But you certainly can: py> isinstance(True, int) True py> isinstance(0.0, int) False However, you can also ask: py> isinstance(True, bool) True py> isinstance(1, bool) False or even: py> type(True) == type(1) False but, I believe, using type() is frowned upon. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
