On 27/07/13 05:41, Steven D'Aprano wrote:
It's only a happy coincidence that bool(1) returns True. So does
bool(-9) after all...
It's more than just a happy coincidence. True actually equals 1.
For backwards compatibility, True == 1 and False == 0 had to remain the
case. So the bool type is actually a subclass of int, but restricted to
only two values. The side effect of this is you can do this:
True + 2
=> returns 3
Most of what you said I knew, but I didn't realize it went so far as
allowing arithmetic! Now I'm on the side of that being a bad thing.
Booleans should be as distinct from numbers as chars
are from strings... ;-)
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
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