import_checker.py	WJ106
Copyright (C) 2006  Walter de Jong <walter@heiho.net>

Python is a fine programming language. There is one horrendous thing
with it though, that bites even the most experienced python programmers
every now and then: the scope of variables.

We've been taught to use the keyword 'global', and heartily do so.
Still, problems occur when running into a "recursive import" problem.
Example:

### program A ###

import B

var = 0

if __name__ == '__main__':
	var = 10
	B.doit()


### module B ###

import A

def doit():
	print A.var

### end of example ###

Module B will see A.var having value 0, even though in program A
we assigned it a value of 10. Python is right and it is not a python
bug, but it is $#@! confusing and it is being caused by the recursive
import; A imports B, and B imports A.

The import_checker.py is a tool that detects recursive imports.


This problem only occurs for global variables in modules.
The best way of solving the problem is to put 'var' into a new module C,
and import C from both A and B.

Good luck and greets,

     --Walter <walter@heiho.net>

EOB