先找本地变量，再找全局变量
改变全局变量：
1 name = "A"
2 def d1():
3 name = "B"
4 def d11():
5 nonlocal name
6 name = "C"
7 d11()
8 print(name)
9
10 print(name)
11 d1()
12 print(name)
#输出结果：
‘‘‘
A
C
A
‘‘‘
改变本地变量：
1 name = "A" 2 def d1(): 3 name = "B" 4 def d11(): 5 global name 6 name = "C" 7 d11() 8 print(name) 9 10 print(name) 11 d1() 12 print(name)
#输出结果：
‘‘‘
A
B
C
‘‘‘
原文：https://www.cnblogs.com/ding-yuan/p/14878298.html