Get all the instances of one class

[Matt Nordhoff]

Tommy Nordgren wrote:
> class MyClass : a_base_class
>       memberlist=[]
> 
> #  Insert object in memberlist when created;
> #  note: objects won't be garbage collected until removed from memberlist.

Just to say, if you wanted to go about it that way, you could avoid the
garbage collection problem by using weakrefs:

<http://docs.python.org/lib/module-weakref.html>
--