[Zope] Re: [Zope-CMF] Persistent dictionaries

[Dieter Maurer]

Thomas Olsen writes:
 > On Sunday 26 August 2001 00:09, Dieter Maurer wrote:
 > > Thomas Olsen writes:
 > >  > Say you have an instance of a class MyClass with attributes myattr1 and
 > >  > myattr2; then you change the class definition for MyClass adding
 > >  > myattr3. 
 > >   2. Python calls "__getattr__" only the normal lookup was
 > >      not successful. The normal lookup will find
 > >      the class attribute "myattr3", "__getattr__" would
 > >      not be called.
 > 
 > But if the object was instantiated before adding myattr3 to the class 
 > definition the objects __dict__ wouldn't contain it and you would get an 
 > AttributeError when trying to access it if you didn't implement __getattr__?
The class dict is searched dynamically. Attributes are not
copied at instance creation time.
It is not necessary to implement "__getattr__" for this.


Dieter