Newbie namespace question

Steve Holden steve at holdenweb.com
Wed Dec 22 16:05:34 CET 2004


bcarlso at gmail.com wrote:

> I have a variable that I want to make global across all modules, i.e. I
> want it added to the builtin namespace.  Is there a way to do this?
> 
Of course: you can do *anything* in Python. I'm not sure this is to be 
recommended, but since you ask ... if you have

# mymod.py
print myname

then in some other module (and here specifically in the interactive 
interpreter) you can bind a value to "myname" in __builtins__ and it 
will be seen by mymod.py when it's imported:

  >>> __builtins__.myname = "MyValue"
  >>> myname
'MyValue'
  >>> import mymod
MyValue
  >>>

Having said all that, you have to be careful, since it's necessary to 
explicity assign to __builtins__.myname to change the value - if you 
just assign to myname then you create a new myname in the module's 
global namespace that will make the name in __builtins__ inaccessible.

So, what with that plus the way the names automagically appear it's 
probably something to relegate to the "definitely not best practice" 
category.

regards
  Steve
-- 
Steve Holden               http://www.holdenweb.com/
Python Web Programming  http://pydish.holdenweb.com/
Holden Web LLC      +1 703 861 4237  +1 800 494 3119



More information about the Python-list mailing list