此问题已在此处找到答案：

如何针对单个值测试多个变量(（27个答案）
为什么'a==x或y或z'的计算结果总是为真(（五个答案）
两天前关门了。
刚开始学习python，我一直在做一些宠物项目。在这个过程中，我决定使用or操作符。当我将它添加到一个if语句时，它按预期工作，但当我将它添加到其他3个if语句时，它只运行第一个if语句。

while True:

    operation = input("What order of operation would you like to use(Addition/A ,Subtraction/S ,Multiplication/M, Division/D)?")

    if operation == "Addition" or "a" :
        while True:
            Set_Number = int(input("Starting Number: "))
            counter = Set_Number
            print(counter)

            number = int(input("Add:"))
            add_count = number
            counter += add_count
            print(f"Your Answer is " + str(counter))

    if operation == "Multiplication" or "m" :
        while True: 
            Set_Number = int(input("Starting Number: "))
            counter = Set_Number
            print(counter)

            number = int(input("Multipled By:"))
            add_count = number
            counter = counter * add_count
            print(f"Your Answer is " + str(counter))

    if operation == "Division" or "d" :
        while True:
            Set_Number = int(input("Starting Number: "))
            counter = Set_Number
            print(counter)

            number = int(input("Divided By:"))
            add_count = number
            counter = counter/add_count
            print(f"Your Answer is " + str(counter))

    if operation == "Subtraction" or "s" :
        while True:
            Set_Number = int(input("Starting Number: "))
            counter = Set_Number
            print(counter)

            number = int(input("Subtracted By:"))
            add_count = number
            counter = counter - add_count
            print(f"Your Answer is " + str(counter))

结果

What order of operation would you like to use(Addition/A ,Subtraction/S ,Multiplication/M, Division/D)?m
Starting Number: 8
8
Add:1
Your Answer is 9
Starting Number:

我不知道如何修复。我需要帮助。