Class variable inheritance

Terry Reedy tjreedy at udel.edu
Tue Sep 8 15:52:48 CEST 2009


HPJ wrote:
>> Makes sense to me. To step through what's happening:
>>
>>>>> A.n, B.n
>> (0, 0)
>>
>> Here, the lookup on B.n fails (that is, B itself has no variable n),
>> and thus falls back to A.n
> 
> See, this is what tripped me up, right at the beginning. I thought B
> would inherit (as in copy) the variable n from A.

Python does not copy objects unless asked to.
Inheritance is a link request, not a copy request.

> Can you point out to me which part (or parts) of the Language
> Reference says this is the way it's supposed to be?

I could, but I will let you read and find what it says about class 
attributes.

tjr




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