python 中全局变量的修改

#! /usr/bin/python

a = 1
b = [2, 3]
c = 1

def func():
a = 2
print ("in func a:", a)
b[0] = 1
print ("in func b:", b)
global c
c = 3
print ("in func c:", c)

if __name__ == '__main__':
print ("before func a:", a)
print ("before func b:", b)
print ("before func c:", c)
func()
print ("after func a:", a)
print ("after func b:", b)
print ("after func c:", c)