python -07-简单计算器

假如:输入7.5 * 3.2 会报错, int类型
    成float型 之后 5.5 * 3.5 = 15 
  

a1 = int(input("请输入第一个数字:"))
n = input("请输入运算符:")
b1 = int(input("请输入第一个数字:"))

if n == "+":
    print("%d %s %d = %d" % (a1, n, b1,(a1 + b1)))

elif n == "-":
    print("%d %s %d = %d" % (a1, n, b1, (a1 - b1)))

elif n == "*":
    print("%d %s %d = %d" % (a1, n, b1, (a1 * b1)))
elif n == "/":
    print("%d %s %d = %d" % (a1, n, b1, (a1 % b1)))