gistfile1.txt

% cat main.py
from config import config, set_config, print_config

print "1: %s" % (config)
set_config({'hello': 'world'})
print "3: %s" % (config)
print_config()

% cat config.py
config = None

def set_config(new_config):
    global config
    config = new_config
    print "2: %s" % config

def print_config():
    print "4: %s" % config

% python main.py
1: None
2: {'hello': 'world'}
3: None
4: {'hello': 'world'}

Line 3 above should be {'hello': 'world'}. I have no idea why it's not. Anyone know?

See Import confusion: http://effbot.org/zone/import-confusion.htm
Use

import config
print config.config
config.set_config("foo")
print config.config


Output:

None
foo


If you change from config import config, set_config to import config (and then update the calls to be config.set_config, etc), then it works as you expect.

The trick is that each module (or in this case, file) has its own "global" scope. When you do from config import config, that actually creates a copy of config.config and places it in the current scope. If you do

import config
print config.config

then you're referencing the config in the other scope, and it does what you expect.

It's beyond import confusion. when you assign config with new_config you're replacing the old config with a new object id. To fix it do config.py like so:

config = {}

def set_config(new_config):
    global config
    config.update(new_config)
    print "2: %s" % config

def print_config():
    print "4: %s" % config

Just to be clear, I do not want to write:

config.config

I want to just be able to write config and have it work. Thanks to Dan I think I at least know what the problem is now. :)