python代码输入一段字符串大小写转换

num8 = input("请输入:")

for i in range(len(num8)):
    if ord(num8[i]) >= 97 and ord(num8[i]) <= 122:

        print(chr(ord(num8[i]) - 32),end = "")

    elif ord(num8[i]) >= 65 and ord(num8[i]) <= 90:

        print(chr(ord(num8[i]) + 32),end = "")
    else:

        print(num8[i],end ="")