global, nonlocal

global_nonlocal.py

a = 0
a2 = 100

def main():
    global a, a2
    print('a2', a2)
    print(a)
    a += 1
    print(a)
    a += 5

def f():
    a = 1
    b = 2
    def f2():
        nonlocal a
        print('a', a)
        a += 2
        print('a', a)
        a += 2

        def f3():
            nonlocal a
            print('a', a)
            a += 2
            nonlocal b
            print('b', b)
            b += 2

        f3()
    f2() 
    print('a', a)
    print('b', b)


if __name__ == "__main__":
    print(a)
    a += 1
    print(a)
    main()
    print(a)

    print("====")
    f()
    print(a)

0
1
a2 100
1
2
7
====
a 1
a 3
a 5
b 2
a 7
b 4
7