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persisting data within a module

Peter J. Bismuti peter.j.bismuti at boeing.com
Mon Nov 12 18:30:33 EST 2007 
I'm having trouble understanding how namespaces work in modules.  I want to 
execute a module within the interpreter and then have values that are 
calculated persist so that other modules that get executed can retrieve them. 

For example, consider the two simple modules below.  The first method fails 
and I'm not sure exactly why.  (Note:  assume one instance of an interpreter.  
In my case a 3rd party software tool that starts an interpreter when it 
launches).  


Two alternate ways of running it:

1. (FAILS: RESULTS A = 0)  Use the module "test" itself as the driver using 
the conditional statement if (__name__=="__main__"):

test.py
run2.py

or, 

2.  (SUCCES: RESULTS A = 10)   Use "run.py" as the driver.  

run.py
 



_________test.py__________________


import sys,os

A = 0

def getA():
  global A
  return A

def run():
  global A
  A = 10

if (__name__=="__main__"):
  run()


_________run.py__________________

import test

test.run()
print "A = " + str(test.getA())



_________run2.py__________________

import test

print "A = " + str(test.getA())

-- 


Peter Bismuti
Boeing Information Technology
Renton, WA
(425) 234-0873 W
(425) 442-7775 C
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