En Fri, 30 Oct 2009 00:29:27 -0300, Steven D'Aprano
<st...@remove-this-cybersource.com.au> escribió:
On Thu, 29 Oct 2009 10:31:03 -0700, AK Eric wrote:
2/ in Python, "global" really means "module-level" - there's nothing
like a "true" global namespace.
Isn't that __main__?
Well there you go, I just learned something new.
I was going to say "No, every module has its own __main__", and say that
the only truly global namespace was builtins, which you really shouldn't
mess with. But then I decided to just try it, and blow me down, it works!
[st...@sylar ~]$ cat set_parrot.py
import __main__
__main__.parrot = "Norwegian Blue"
[st...@sylar ~]$ cat get_parrot.py
import __main__
print __main__.parrot
[st...@sylar ~]$ python
Python 2.5 (r25:51908, Nov 6 2007, 16:54:01)
[GCC 4.1.2 20070925 (Red Hat 4.1.2-27)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
import set_parrot
import get_parrot
Norwegian Blue
I'm sure there are all sorts of odd problems this would lead to in large
scale code, but it's a neat trick to know.
It isn't a neat trick anymore once you realize the name '__main__' isn't
special.
Replace __main__ with foo, or config, or whatever, and you get the same
results. Ok, there is a catch: a file with that name must exist, at least
an empty one...
You're just importing the same module from two places; changes done in one
place are reflected in the second place, like with any other object.
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
