想知道为什么这段代码会导致语法错误？ [关闭]

You try to tell him if choice == A. This means that A is a variable, and if A is not defined, it will not work ! You forgot to put 2 " to make it a string, and then to be able to compare it. So now your code looks like:

  # Ask for user input
    choice = input ("Enter the letter A or B: ")

    # Detect choice
    if choice == "A":
        print ("You entered A!")
    elif choice == "B":
        print ("You enetered B")
    else:
        print ("You didn't enter A or B!")

由于输入存储为字符串，因此需要将其与字符串进行比较：

if choice == 'A':
    print ("You entered A!")
elif choice == 'B':
    print ("You enetered B")
else:
    print ("You didn't enter A or B!")

您必须写“ A”和“ B”而不是A和B。引号之间的单词是一个字符串，没有引号的是变量。您写入选择变量的是一个字符串