def func(x):
    print("x is ", x)
    x = 2
    print("Changed local x to ", x)
  
x = 50
func(x)
print("x is still ", x)
 
运行结果是：
 
 
('x is ', 50)
('Changed local x to ', 2)
 
？？？？？？？？？
这里的X竟然还是50，这就是Python里所谓的局部变量。。。。。
('x is still ', 50)