Peter Otten wrote:
Gabriel Rossetti wrote:
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.
Imported modules are cached, so this problem shouldn't occur unless you use
A.py as your main script. In this case it will be cached as "__main__", and
if you import it elsewhere a second copy will be executed and cached as "A".
To fix it create a wrapper script that doesn't create any objects that will
be used elsewhere, e. g.
#!/usr/bin/env python
import A
A.main()
assuming the function A.main() contains the code to start your application
and invoke that instead of A.py
Peter
Thank you Peter, I understand better now. I am indeed using A.py as my
main script. I will create a launcher then, thank you.
Gabriel
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