Nested class structures

[Larry Bates]

It is a little hard to understand what you want but you
may just want to put class instances in a list.

class anon:
    pass

class class1:
    def __init__(self):
      self.l=[anon(), anon(), anon()]

Now create an instance of class1:

x=class1()

x.l[0] will point to first instance of anon class
x.l[1] will point to second instance of anon class
x.l[2] will point to third instance of anon class

May not be what you are looking for.

Larry Bates
Syscon, Inc.


"OKB (not okblacke)" <BrenBarn at aol.com> wrote in message
news:Xns95607B54E1208OKB at 130.133.1.4...
>     For a variety of reasons, I'm interested in putting together some
> code that will allow me to created structures out of nested classes,
> something like:
>
> class class1:
>     def methA(self):
>         print "Some code here"
>     class class2:
>         propA = "A"
>         def methB(self):
>             print "Some more code here"
>     class class3:
>         # etc.
>         class class4:
>             pass
>             #etc
>
>     The main problem is that Python does not seem to provide enough
> information about the lexical context of definitions like this.  In
> particular, I would like the ability to have some of the nested classes
> be "anonymous" -- that is, I don't want to have to worry about choosing
> identifiers for them.  I'd LIKE to do this:
>
> class class1:
>     class anon: pass
>     class anon: pass
>     class anon: pass
>
>     . . . and somehow intercept or monitor the name-binding that's
> going on there so I wind up with three separate classes which are bound
> to uniquely named attributes of class1.  But I can't do this because
> each anon stomps on the previous name binding, and there doesn't seem to
> be a way to intervene and bind a new attribute in class1, because class1
> isn't really created until after all the nested class definitions
> happen.
>
>     I've been playing around with various metaclass approaches, but I
> can't seem to get it to really work.  (In the nested class structures,
> the metaclass instantiations happen from the bottom up, and that's the
> main snag.)  Are there any hooks or hacks that would allow me to affect
> the way nested class definitions are bound to the attribute names of an
> enclosing class definition?  Or alternatively, a way to construct on the
> fly a separate list or tree that reflects the nesting structure?
>
> -- 
> --OKB (not okblacke)
> Brendan Barnwell
> "Do not follow where the path may lead.  Go, instead, where there is
> no path, and leave a trail."
> --author unknown