Python 回文程序无法运行

我用 python 编写了一个简单的程序，它检查句子是否是回文。但我不明白为什么它不起作用。结果始终为 False。有谁知道出了什么问题吗？

def isPalindrome(word):
    # Removes all spaces, and lowercase the word.
    word = word.strip().lower()
    word = word.replace(" ", "")

    # If the length of the word is less than 1, means its a palindrome
    if (len(word) <= 1):
        return True

    # Compares the first and the last character of the word.
    # If it is the same, calls the function again with the same word,
    # without its first and last characters. If its not the same, its
    # not palindrome
    else:
        if word[0] == word[-1]:
            isPalindrome(word[1:-1])
        else:
            return False


sentence = input("Enter a sentence: \n")

if (isPalindrome(sentence)):
    print("The sentence %s is palindrome." % sentence)
else:
    print("The sentence %s is NOT palindrome" % sentence)

您没有返回函数的结果。

代替 ：

if word[0] == word[-1]:
    isPalindrome(word[1:-1])

with

if word[0] == word[-1]:
    return isPalindrome(word[1:-1])