Is there a way to access outer class in the nested class in python?

Question

just a very simple thing, is there a way to access outer class from the inner class definition, like this:

class Model:
  class Options:
    model = Model   <-- error!

I nest Options inside Model because semantically these Options exist only in the scope of model, so it seems appropriate.

Thanks, Alex

Why would you want to store the (outer) class in a (inner) class variable? — user395760
– user395760, Commented Jul 27, 2011 at 20:17
I think this is more of a design implementation flaw than a language problem. — g.d.d.c
– g.d.d.c, Commented Jul 27, 2011 at 20:19
I don't have to store it in a variable, but I'd like to use the outer class in the inner class, since they are semantically related. Variable is just an example... — Alex Kreimer
– Alex Kreimer, Commented Jul 27, 2011 at 20:23
You can, but not at class level (as that's evaluate at class definition time, while methods usually don't get called before the class definitions finish running). — user395760
– user395760, Commented Jul 27, 2011 at 20:29

Hgeg · Accepted Answer · 2011-07-27 20:20:43Z

2

I am not sure this is exactly what you wanted but try:

class Model:
    class Option:
        @property
        def model(self): return Model

answered Jul 27, 2011 at 20:20

Hgeg

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Comments

Tom Pohl · Accepted Answer · 2011-07-27 20:25:17Z

1

Well, you can at least instantiate the outer class in a method of the inner class:

class Model:
    class Options:
        def __init__(self):
            model = Model()

answered Jul 27, 2011 at 20:25

Tom Pohl

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2 Comments

agf Over a year ago

but then if you instantiate Options in Model.__init__ you'll recurse.

warvariuc Over a year ago

just do model = Model instead of model = Model()

warvariuc · Accepted Answer · 2011-07-28 05:40:16Z

1

Try:

class Model:
    pass

class Options:
    model = Model

answered Jul 28, 2011 at 5:40

warvariuc

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Comments

kindall · Accepted Answer · 2011-07-28 05:55:29Z

0

Another solution is to do the assignment after the class definition.

class Model:
  class Options:
    pass

Model.Options.model = Model

answered Jul 28, 2011 at 5:55

kindall

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