[Tutor] Calling super classs __init__?

tiger12506 keridee at jayco.net
Sat Mar 22 05:11:37 CET 2008

Woah. Either you're leaving out essential info, or python got a lot more 

Firstly, super returns all base classes. How? Does it return a tuple of 
them, or a container object, or is this something horribly worse such as 
syntactic sugar?

It doesn't make sense for it to return a tuple, then super().__init__ would 
call the init method of the tuple, not each class, so then syntactic sugar 
would have to be involved. I doubt that..

A container object could use __getattr__ to magically call each of the 
__init__ methods of the contained class references.
The most logical is the container object. But that leaves things open for 
duplicate calls to __init__
So the container would have to keep track of the base classes it has already 
called... which might be the ordered list __mro__, but those are class 
specific, not global, so each super class would not know if an __init__ has 
been called or not... But then again, you would need duplicate calls because 
each level of super would need different initiation.

I apologize. Would you care to explain this a little more technically? 
Specific and accurate are better than translated into layman's terms. I've 
been with python for a while now. thanks.

>Actually, super returns all base classes, all in it's own time.
>Basically, every class has a member __mro__, that contains a
>consistently ordered list of classes.
>super needs the class from where it is being called to locate the right
>place in the __mro__ and to hand you a wrapper around self for the next
>base class in this list.
>This way, if all classes use super, they can cooperativly call all
>implementations of a given method.
>That's the theory. In practice there are a number of pitfalls which
>makes super problematic. ;)

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