>>> class Me (Thread):
...     def __init__ (self):
...             Thread.__init__ (self)
...             self.x = 0
...             self.target = self.foo
...             self.start ()
...     def foo (self):
...             while True:
...                     self.x += 1
...
>>> class Me2 (Thread):
...     def __init__ (self):
...             Thread.__init__ (self)
...             self.target = self.foo
...             self.start ()
...     def foo (self):
...             global x
...             while True:
...                     x += 1
...
>>> x = 0
>>> me = Me ()
>>> me.x
0
>>> del me
>>> me2 = Me2 ()
>>> x
16112383850
>>> x
16120480574