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Date: Wed, 05 Mar 2014 14:37:15 +0100
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Xref: csiph.com comp.lang.python:67846

Op 04-03-14 16:25, Chris Angelico schreef:

> On Wed, Mar 5, 2014 at 2:19 AM, Jerry Hill <malaclypse2@gmail.com> wrote:
>> Out of curiosity, do you think we should be doing truth checking with
>> 'is'?  True and False are singletons, and it seems to me that the
>> justification for idenity versus equality should be just as strong
>> there, but I don't think I've ever seen anyone even suggest that.
> Normal truth testing is done like this:
>
> if cond:

In an other language with real booleans where an if only accepts a
boolean that would be true. In python this is testing for "something."

> This isn't truth testing, this is checking the identity of what's in cond:
>
> if cond is True:
>
> And that's specifically testing for something much tighter than
> truthiness. As you can see from my stats above, that's actually fairly
> rare. Usually you'd just accept that True, 1, "yes", [1,2,3], and
> 1.2345 are all equally true.

No I usually don't accept that. A number different from 0 is not the same
as a none-empty list. I usally don't want to treat them the same.

-- 
Antoon Pardon