Scoping example. : global « Function « Python Tutorial

x = 1 # global variable

def a():  
   x = 25
   print "\nlocal x in a is", x, "after entering a"
   x += 1
   print "local x in a is", x, "before exiting a"

def b():
   global x
   print "\nglobal x is", x, "on entering b"
   x *= 10
   print "global x is", x, "on exiting b"

print "global x is", x

x = 7
print "global x is", x

a()
b()
a()
b()

print "\nglobal x is", x

10.10.global
	10.10.1.	only the most local and global namespaces can be modified
	10.10.2.	global Statement
	10.10.3.	Scoping example.
	10.10.4.	Demonstrates global variables
	10.10.5.	The global Statement
	10.10.6.	declare it in a global statement:
	10.10.7.	Within a function, you can't use both local and global versions of the same name