浮点数四则运算和格式化输出

Question

输入两个浮点数，计算加减乘除，结果怎么用str.format()保留三位数字？并且输出的是完整的计算等式，符号前后有一个空格

Answer 1

import sys

if __name__ == "__main__":
    num1 = float(sys.argv[1])
    num2 = float(sys.argv[2])

    print(type(num1))
    print(type(num2))

    print("{0} + {1} = {2}".format(num1, num2, round(num1 + num2, 3)))
    print("{0} - {1} = {2}".format(num1, num2, round(num1 - num2, 3)))
    print("{0} * {1} = {2}".format(num1, num2, round(num1 * num2, 3)))
    print("{0} / {1} = {2}".format(num1, num2, round(num1 / num2, 3)))

简单说明：

1. 程序为了方便，直接使用sys.argv直接获取参数，执行时需要传递两个数值