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I was using a yes/no loop to make an infinite loop which would end when user enters no or No but the program was not working properly. I know the what the error is but i don't know why is it occuring like this. Can anyone tell how to fix the error without changing my initial program

当我使用这段代码时它可以工作但是当我使用 if a=='yes' 或 'Yes' 和 elif a=='no' 或 'No' 以某种方式输出显示 if 语句的打印语句即使我输入编号

我的程序没有 OR 条件

while True:
    a = input("Enter yes/no to continue")
    if a=='yes':
        print("enter the program")
    elif a=='no':
        print("EXIT")
        break
    else:
        print("Enter either yes/no")

我的 OR 条件初始程序

while True:
    a = input("Enter yes/no to continue")
    if a=='yes' or 'Yes':
        print("enter the program")
    elif a=='no' or 'No':
        print("EXIT")
        break
    else:
        print("Enter either yes/no")

解决方案

在一条or语句中，您必须a与所有表达式中的值进行比较：

while True:
    a = input("Enter yes/no to continue")
    if a == 'yes' or a == 'Yes':
        print("enter the program")
    elif a == 'no' or a == 'No':
        print("EXIT")
        break
    else:
        print("Enter either yes/no")

一种更 pythonic 的方法是.lower()在你的情况下使用。例如：

a == 'yes' or a == 'Yes'  # is equeal to:
a.lower() == 'yes'