global and import

[Fredrik Lundh]

Nathan Clegg <nathan at islanddata.com> wrote:
> I'm having a little trouble understanding how global and import interact. 

quick answer: they don't.

"global" doesn't have anything to do with global
variables in the usual sense; it's just a way to
tell Python to look in the *module* namespace
instead of in the *local* namespace when you're
inside a function or a method.

> Currenly I have a script that includes a couple of global variables that
> allow for a small amount of communication between multiple threads and
> signal handlers.  I would like to move some of the functions to separate
> modules for several reasons, but need to maintain just the two global
> variables between them.

put these two variables in a common module,
and access them explicitly from the others. and
just forget about the global statement.

consider this:

common.py:

    mode = 0 # default

onemodule.py:

    import common

    def myfunc(self):
        print "look ma, no global"
        common.mode = 1
        mylib.dosomething()
        common.mode = 0

twomodule.py:

    import common

    def new_great_taste(argh):
         compute(common.mode, argh)

etc.

</F>