1. a = 100
    2. a += 1 # 等价于a = a + 1
    3. print(a)
    4. b = 10
    5. b -= 1 # b = b - 1
    6. print(b)
    7. c = 10
    8. c += 1 + 2
    9. print(c) # 输出 13
    10. # 注意:先计算复合赋值运算符右侧表达式,在计算复合赋值运算(先计算右后赋值计算)
    11. c = 10
    12. # c = 10 + 1 + 2
    13. # c += 3 -- c = c + 3
    14. c += 1 + 2
    15. print(c)
    16. d = 10
    17. d *= 1 + 2
    18. print(d)