如何用Python编写两步计算器代码？

Question

我想建立一个两步计算器。步骤1:num1+num2>；打印结果。第二步取打印结果+num3。我如何编码它，让用户有3个初始输入和答案是使用以下两个用户输入的一部分

这是我的代码，我需要更正什么

num1 = float(input("Enter your first number: "))
op = input("Enter your operator: ") 
num2 = float(input("Enter your second number: "))
op2 = input("Enter second operator: ")
num3 = float(input("Enter third number: "))

if op == "+":
    print(num1 + num2)
    result = num1 + num2
elif op == "-":
    print(num1 - num2)
    result = num1 - num2
elif op == "*":
    print(num1 * num2)
    result = num1 * num2
elif op == "/":
    print(num1 / num2)
    result = num1 / num2
else:
    print("Invalid Operator")


if result == float and op2 == "+":
    print(result + num3)
elif result == float and op2 == "-":
    print(result - num3)
elif result == float and op2 == "/":
    print(result / num3)
elif result == float and op2 == "*":
    print(result / num3)
else:
    print("Invalid Operator")

op2输入不工作或者没有得到结果