Wow, this seems so basic, but I can't get it to work. All I need to do is store a global dict which can be accessed and modified from other modules & threads.

What's the "best practices" way of achieving this?

test.py

import testmodule

class MyClassA():
    def __init__(self, id):
        self.id = id

if __name__ == '__main__':
    global classa_dict
    classa_dict = {}
    classa_dict[1] = MyClassA(1)
    classa_dict[2] = MyClassA(2)

    testing = testmodule.TestModule()

testmodule.py

class TestModule():
    def __init__(self):
        global classa_dict
        print classa_dict[2]

output

$ python test.py 
Traceback (most recent call last):
  File "test.py", line 13, in <module>
    testing = testmodule.TestModule()
  File "/path/to/project/testmodule.py", line 4, in __init__
    print classa_dict[2]
NameError: global name 'classa_dict' is not defined