Jussi Piitulainen wrote:
> Thibault Langlois writes:
>
>> Hello,
>>
>> $ python
>> Python 2.7.4 (default, Sep 26 2013, 03:20:26)
>> [GCC 4.7.3] on linux2
>> Type "help", "copyright", "credits" or "license" for more information.
>> >>> 1 > 0 == True
>> False
>> >>> (1 > 0) == True
>> True
>> >>> 1 > (0 == True)
>> True
>> >>>
>>
>> What am I missing here ?
>
> One or both of the following:
>
> >>> 0 == True
> False
> >>> True and False
> False
> >>> 1 > 0
> True
>
> Or the fact that (1 > 0 == True) means ((1 > 0) and (0 == True)),
> where each expression in such a chain is evaluated once, though in
> this case it really does not matter since 0 is a literal.
>
> Hm, I don't know if the evaluation short-circuits. I think not, but
> I've never needed to know, and I don't need to know now.
It is easy to check though:
>>> def zero():
... print("zero")
... return 0
...
>>> def one():
... print("one")
... return 1
...
>>> def true():
... print("true")
... return True
...
>>> one() > zero() == true()
one
zero
true
False
>>> zero() > one() == true()
zero
one
False
So yes, evaluation does short-curcuit.
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