Initializing an attribute that needs the object

David Pratt fairwinds at
Sat Jun 3 01:17:02 CEST 2006

Hi Bruno. This is certainly what I was missing. Thank you. I am afraid I 
am behind the times with use of object. Will I only use object when I am 
not subclassing? Where will I find a document that provides info on the 
use of object in new style classes? Many thanks.


Bruno Desthuilliers wrote:
> David Pratt a écrit :
>> Hi. I want to have different handlers to do perform logic. The problem 
>> is the Handler requires an instance of the factory since it will use its 
>> own methods in conjunction with methods of the factory.
>> Once I have got a Factory instance I can give it a new handler (see 
>> below). It would be more flexible if I could provide a handle in 
>> constructor - but how to do this when it requires the object itself. 
> Hint : Python classes are objects too.
>> class Factory:
> Do yourself a favour : use new-style classes.
> class Factory(object):
>    def __init__(self, handler_class):
>      self.handler = handler_class(self)
> class SomeHandler(object):
>    def __init__(self, factory):
>      self.factory = factory
> f = Factory(SomeHandler)

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