A certainl part of an if() structure never gets executed.

[Nick the Gr33k]

On 14/6/2013 4:14 πμ, Steven D'Aprano wrote:
> On Thu, 13 Jun 2013 17:26:18 +0300, Νικόλαος Κούρας wrote:
>
>> i just want 4 cases to examine so correct execute to be run:
>>
>> i'm reading and reading and reading this all over:
>>
>> if '-' not in ( name and month and year ):
>>
>> and i cant comprehend it.
>
> Don't just read it. Open the interactive interpreter and test it.
>
> name = "abcd"
> month = "efgh"
> year = "ijkl"
>
> print(name and month and year)
>
> If you run that, you will see what the result of
> (name and month and year) is. Now, ask yourself:
>
> "k" in (name and month and year)
>
> True or false? Check your answer:
>
> print("k" in (name and month and year))


 >>> name="abcd"
 >>> month="efgh"
 >>> year="ijkl"

 >>> print(name or month or year)
abcd

Can understand that, it takes the first string out of the 3 strings that 
has a truthy value.

 >>> print("k" in (name and month and year))
True

No clue. since the expression in parenthesis returns 'abcd' how can 'k' 
contained within 'abcd' ?

 >>> print(name and month and year)
ijkl

Seems here is returning the last string out of 3 strings, but have no 
clue why Python doing this.

 >>> print("k" in (name and month and year))
True
 >>>

yes, since expression returns 'ijkl', then the in operator can detect 
the 'k' character within the returned string.

-- 
What is now proved was at first only imagined!