如何在句子中找到以相同字母开头和结尾的单词？

Question

有没有办法在python中编写“for”循环和“If Else”来搜索句子并找到以相同字母开头和结尾的单词数？我试过写这样的东西：sentence = "Mom knock the door"list = sentence.split()for word in sentence:    if ...

Answer 1

只需将字符串开头的字符与字符串结尾的字符进行比较，如下所示：

if word[0] == word[-1]:

如果它不应该区分大小写，请先通过调用降低单词：

word = word.lower()

Answer 2

words_list = sentence.split()

new_words_list = []

for word in words_list:

    if word[0] == word[-1]:

        new_words_list.append(word)

print('Number of words that starts and ends with same letter - {}'.format(len(new_words_list)))

你也可以用列表理解来做到这一点：

new_words_list = [word for word in words_list if word[0] == word[-1]]

如果您不想让它区分大小写，请使用word[0].lower()andword[-1].lower()而不是word[0]andword[-1]

Answer 3

上面的答案都很聪明，我更喜欢用函数式编程的方式来处理，像这样：

sentence = "Mom knock the door"

def is_same_letter_at_begin_end(word):

    return word and word[0].lower() == word[-1].lower()

target_words = list(filter(is_same_letter_at_begin_end, sentence.split()))

print(target_words)

print(len(target_words))