python - 为什么我在 elif 行中收到无效的语法错误？

Question

有人可以告诉我为什么我在这里遇到无效的语法错误（python 3）：

a = input("Do you want the alphabets in the pattern in ascending order or descending order? (Yes/No) ")
if a == "Yes" or "yes":
    b = 65
    elif a == "No" or "no":
        b = 88
    else print("Invalid input")
for x in range (5,0,-1):
    for y in range (0,x):
        print(" ", chr(y+b), end = "")
    print()

标签： python

Answer 1

第一个问题是缩进。elif并且else必须与各自的if. 此外，在预期elsea之后，结果在下面的行中。:在这里，我更改了您的代码以使其正常运行：

a = input("Do you want the alphabets in the pattern in ascending order or descending order? (Yes/No) ")
if a.lower() == 'yes':
    b = 65
elif a.lower() == 'no':
    b = 88
else:
    print("Invalid input")
for x in range (5,0,-1):
    for y in range (0,x):
        print(" ", chr(y+b), end = "")
    print()