two new wrinkles to the general class!

[Jeff Shannon]

syd wrote:

>>>1) Because I've got many "container" type classes, the best route
>>>      
>>>
>would obviously seem be to subclass each to a general "container".  Ie,
>
>class Library_A(Container): ...
>class Library_B(Container): ...
>
>The problem: in the current setup, a library_a.get_continent('Europe')
>would pass back an instance of Container and *not* Library_A.  The
>obvious implication is that any attributes/method specific to Library_A
>are gone. 
>

As I understand it, your object's (most derived) type will be stored as 
self.__class__.  So, in order to have Library_A create more Library_A 
instances, and Library_B create more Library_B instances, you can 
instead do something like:

    new_copy = self.__class__()


>2) I've got a bunch of "get_foo" type things where "foo" is not an
>  
>
>attribute of the component class but rather a method.  [...]
>
>Above, we use getattr() to grab the attribute on-the-fly.  Can we grab
>a method on-the-fly, too?  
>

Sure -- methods are just attributes that happen to be callable.  You get 
a method reference in the same way that you get any attribute, and you 
call it the same way that you call any function reference:

    method = Collection.get_foo('bar')
    method()

will call whatever method get_foo('bar') returns.

Jeff Shannon
Technician/Programmer
Credit International