>>> foo = None
>>> def bar():
... global foo
... if False:
... foo = 'spam'
... print foo
...
>>> bar()
None
# Python needs to know in the beginning of the function if you plan on using the local or the
# global version of the variable. Remember that you can't declare variables in python. You can
# only bind them. Read more in the naming and binding section of the python reference documentation
# https://docs.python.org/2.3/ref/naming.html