How to deal with globals during refactoring classes into separate files.

[r0g]

Hi There,

I'm refactoring some old code that uses global variables and was
originally written in one big flat file with a view to nicening it up
and then extending it. The problem I have though is when I move the
various classes out to their own separate files and reimport them back
in they can't see the globals in the main program. Most of the globals
were just constants and so I have been able to factor them out but
there's one that's kind of pivotal that I still need, basically a list
of all the threads I have running, I don't see how I could get rid of
that. Example follows...

The original with global variable and classes all in one file...

dirty_global = "whatever"
class example():
  def print_message(self):
    print "Sure, "+dirty_global
a = example()
a.print_message()

>>>Sure, whatever


But when I put the class in  its own file and then import it back in...


from example_class import example
dirty_global = "whatever"
a = example()
a.p()

>>>NameError: global name 'dirty_global' is not defined



I had thought declaring the variable using the global keyword at the top
of the file might make it a global 'proper' (as per the manual) or that
using it at the top of the class file might somehow allow the class to
see the variable in file it was called from but clearly my understanding
of python namespaces and scoping isn't quite there yet as neither of
these seem to make any difference.

How can get my classes to see this 'dirty_global' variable again?

Thanks,

Roger.