python - 如何使用len且不区分大小写？

Question

stop = False
text_count = 0
while stop is False:
    int_string = input("What is the initial string? ")
    int_string = int_string.lower()
    for a in int_string:
        for a in b:
            text_count += 1
    if text_count < 3:
        print("Error: string must have at least 3 characters.")
    elif len(int_string) != 'X' or len(int_string) != 'x' or len(int_string) != '_':
        print("Error: string must contain only X and _.")

该字符串的长度必须至少为 3 个字符，并且只能包含字符“X”、“x”或“_”(下划线) 也不区分大小写

Answer 1

您可以将其转换为 set对象并将其与您允许的字符集进行比较:

while not stop:
    int_string = input("What is the initial string? ").lower()

    if len(int_string) < 3:
        print("Error: string must have at least 3 characters.")
    elif set(int_string) <= {'x', '_'}:
        print("Error: string must contain only X and _.")

a <= b是 a.issubset(b) 的简写.