Is (-1 ==True) True or False? Neither

Steven D'Aprano steve at REMOVE-THIS-cybersource.com.au
Sun Jan 25 07:21:31 EST 2009


On Sun, 25 Jan 2009 03:07:04 +0200, Oktay Şafak wrote:

> The reason is that when
> someone writes (-1 == True) he is clearly, definitely, absolutely asking
> for a boolean comparison, not a numerical one.

If I wrote (-1 == True), and I'm not sure why I would, I would expect to 
get the answer False, because -1 is not equal to True. Many things have 
truth values which are true but not equal to True.

If I wanted bool(-1) == True, I'd write bool(-1) == True. Or, if I was in 
a whimsical mood, I'd write:

((bool(-1) == True) == True) == True  # oh when to stop???

just to illustrate the foolishness of doing boolean equality comparisons 
like that.


-- 
Steven



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