[Tutor] Newbie: "Global" vars across modules

[Alan Trautman]

My favorite method, from a discussion on this list is to create a module and
import it into all modules that need access. I name it myappname_globals.py
and it contains things like database name, debug level, and other constants
that might need changing. A config file is the other option I use if there
is a lot to configure. If debug level is the only reason a command line
argument is safest.

This is the one of the very few cases where I like FROM myappname_globals.py
IMPORT *. this means that the variable names are the same in every case. 

Hope that helps,

Alan



-----Original Message-----
From: Jeremy Oddo [mailto:joddo at apixels.net]
Sent: Wednesday, December 03, 2003 3:43 PM
To: Python Tutor
Subject: [Tutor] Newbie: "Global" vars across modules


I'm guessing this has come up time and time again, but I can't seem to
find the information that I need.

Here's my problem:  I want to create a global variable that EVERY module
can see.  Why?  Because I like to define a "debug_level" variable to print
out debugging information.  I want to define "debug_level", then use it
throughout my main code and modules.  I'm running into problems when I
call an external module that I've written.  Here's the basic idea:

--begin gvars.py--
# Debug Level (0=NONE, 1=Normal, 2=Extended, 3=Verbose)
debug_level = 2


--myFunctions.py--
def ftest():
    if (debug_level = 3):
        print "VERBOSE DB:  This is a verbose statement"
    return 1


--testing.py--
from gvars import *
from myFunctions import *

print "Current debug level is:", debug_level
ftest()



So, testing.py is my main file.  It imports gvars.py which contains my
global variable "debug_level".  The testing.py file prints out
"debug_level" and all is good.  However, when I make the call to "ftest()"
which is a function from A DIFFERENT FILE called "myFunctions.py", it
doesn't see "debug_level" (even if I add the line "global debug_level").

So how can I make a "truly global" global variable?

Thanks!
JO



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