Classes referencing each other
Manuel Bleichner
manuel at prolink.de
Fri Sep 1 04:24:01 EDT 2006
Hello list,
I have searched for some time now, but no result...
I'm having the following problem:
In a module I have a huge number of classes of the form:
class A(object):
connected_to = [B, C]
<other attributes...>
class B(object)
connected_to = [C]
<other attributes...>
class C(object)
connected_to = [A]
<other attributes...>
As you see, classes A and B reference classes that
are not yet defined when the class is being defined.
It will raise a NameError: 'B'.
I know i could solve this by leaving out the definition
of 'connected_to' in A and attach it to the class later on by
A.connected_to = [B, C]
but I would like to avoid this, because in the module
there are about 50 classes that have to be altered from time
to time and it's just incredibly ugly if I have to look for
the attribute definitions in more than one place.
Also, I would like to avoid eval(), because the references
have to be followed very often and that would cause more
CPU load and make the program code uglier :)
If anyone of you knows a neat way to solve this, I'd be
very grateful.
Greetings,
Manuel
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