>>>>> koranthala <koranth...@gmail.com> (k) wrote: >>> That test was designed to treat None as a boolean False, without >>> noticing that numeric 0 is also treated as False and could make the >>> test do the wrong thing. This is an extremely common type of error.
>k> Actually, I felt that 0 not being considered False would be a better >k> option. >k> I had lot of instances where 0 is a valid value and always I had to >k> put checks specifically for that. >k> For me, None and False should be equal to False in if checks, every >k> thing else being considered True. >k> Can someone let me know why 0 is considered equal to False? >k> There should be real good reasons for it, only that I cannot think of >k> one. Originally Python didn't have booleans. Integers were used instead (but not exclusively). 0 was False, everything else True (with a slight preference for 1 as True). Same as in C. Nowadays this is reflected in bool being a subtype of int with False == 0 and True == 1. Actually it is even closer: False and True are just 0 and 1 cast to bool, so to say. -- Piet van Oostrum <p...@cs.uu.nl> URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4] Private email: p...@vanoostrum.org -- http://mail.python.org/mailman/listinfo/python-list
