I'm having a vexing problem with global variables in Python. Please
consider the following Python code:
#! /usr/bin/env python
def tiny():
bar = []
for tmp in foo:
bar.append(tmp)
foo = bar
if __name__ == "__main__":
foo = ['hello', 'world']
tiny()
When I try to run this, I get:
Traceback (most recent call last):
File "./xtalk.py", line 11, in ?
tiny()
File "./xtalk.py", line 5, in tiny
for tmp in foo:
UnboundLocalError: local variable 'foo' referenced before assignment
For some reason, Python can't see the global variable "foo" in the
function tiny(). Why is that?
If I change the code to this:
#! /usr/bin/env python
def tiny():
for tmp in foo:
print tmp
if __name__ == "__main__":
foo = ['hello', 'world']
tiny()
I get this:
hello
world
All of a sudden, tiny() can see the global variable "foo". Very
confusing! Why is it that tiny() sometimes can, and sometimes can't,
see the global variable "foo"?
If anyone can enlighten me about what's going on with Python and
global variables, I would appreciate it!
--
http://mail.python.org/mailman/listinfo/python-list
