如何让我的代码在python中检测字符串的结尾？

Question

我正在尝试编写代码来分割一个没有标点符号的句子.例如,如果用户输入"Hello, how are you?",我可以将句子拆分为['hello','how','are','you']

userinput = str(raw_input("Enter your sentence: "))

def sentence_split(sentence):
    result = []
    current_word = ""
    for letter in sentence:
        if letter.isalnum(): 
            current_word += letter     
        else: ## this is a symbol or punctuation, e.g. reach end of a word
            if current_word: 
                result.append(current_word)
                current_word = "" ## reinitialise for creating a new word
    return result

print "Split of your sentence:", sentence_split(userinput)

到目前为止我的代码工作,但如果我把一个句子没有用标点符号结尾,最后一个单词将不会显示在结果中,例如,如果输入是"Hello, how are you",结果将是['hello','how','are'],我想这是因为没有标点符号告诉代码字符串结束,有没有办法让程序检测到它是字符串的结尾？因此,即使输入"Hello, how are you",结果仍然是['hello','how','are','you'].

Answer 1

我自己并没有尝试调整你的算法,但我认为下面的方法应该实现你所追求的目标.

def sentence_split(sentence):
    new_sentence = sentence[:]
    for letter in sentence:
        if not letter.isalnum():
            new_sentence = new_sentence.replace(letter, ' ')
    return new_sentence.split()

现在运行:

runfile(r'C:\ Users\cat\test.py',wdir = r'C:\ Users\cat')

['你好,你好吗']

编辑:修复了new_sentence初始化的错误.