0 + not 0

Luuk luuk at invalid.lan
Sat Jul 11 13:12:54 CEST 2015


On 11-7-2015 12:38, Irmen de Jong wrote:
> On 11-7-2015 12:26, candide wrote:
>>>>> 0 + not 0
>>    File "<stdin>", line 1
>>      0 + not 0
>>            ^
>> SyntaxError: invalid syntax
>>>>>
>>
>>
>> What is syntactically wrong with 0 + not 0?
>>
>
> I would say that the boolean operator 'not' cannot occur in an arithmetic expression.
> Maybe you meant to use the bitwise not:
>
>>>> 0 + ~0
> -1
>
>
> Irmen
>

It can occur in an arithmetic expression, and 'not' has a higher 
precedence than '+'
(https://docs.python.org/2/reference/expressions.html#operator-precedence)

0 + not 0
should evalutate to
0 + True
1

just like this does:
0 + (not 0)
1


True + True
2

But, it gets confusing......
 >>> not 0 + 1
False
 >>> not 0
True
 >>> True + 1
2
 >>>

i would expect 'not 0 + 1' to return the same value as 'True + 1'




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