Dynamically declared shared constant/variable imported twice problem

Gabriel Rossetti gabriel.rossetti at arimaz.com
Fri May 1 13:18:06 CEST 2009

Hello everyone,

I have three modules A, B, C;

A declares this globally :

  UpdateEvent, UPDATE_EVENT_ID = wx.lib.newevent.NewEvent()

Then they import stuff from each other:

- A imports a constant from module B (in "__main__")
- A imports a class and some constants from module C
- B imports a constant from module A
- C imports UPDATE_EVENT_ID from module A

What happens is that since A imports stuff from B which then in turn
loads something from A, UPDATE_EVENT_ID gets redefined and when A sends
an event to C, C doesn't do anything since it doesn't have the same
UPDATE_EVENT_ID. Does anyone have an idea on how to fix this? If it had
been a statically defined variable then that wouldn't be "bad", but
since it's dynamic it does pose problems. More globally, how cn I
prevent this even with static constants? I don't think it's that great
to redefine the stuff multiple times and I've already had this problem
in the past with a constant dict.

Thank you,

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