Make import module return a variable

Question

I would like to make an imported module behave like an object, ie. an dictionary.

E.g.

import module
print(module['key'])

and in module.py

return {'key':'access'}

This is very easy for Class by inheriting from dict, but how do I do this on a module level?

In particular I want to dynamically built the dictionary in module and return it when module is imported.

I know that there are other solutions such as defining the dict as a var in the module workspace and accessing it via module.var, but I am interested if something like this is possible.

Answer 1

As you point out, you can do this with a class, but not with a module, as modules are not subscriptable.Now I'm not going to ask why you want to do this with an import, but it can be done.

What you do is create a class that does what you want, and then have the module replace itself with the class when imported. This is of course a 'bit of a hack' (tm). Here I'm using UserDict as it gives easy access to the dict via the class attr data, but you could do anything you like in this class:

# module.py
from collections import UserDict
import sys
import types
class ModuleDict(types.ModuleType, UserDict):
 data = {'key': 'access}
sys.modules[__name__] = ModuleDict(__name__)

Then you can import the module and use it as desired:

# code.py
import module
print(module['key']
# access