在 Python 列表中查找特定索引的下一个元素值

Question

我有一个简单的 python 程序来判断一个句子是否是一个问题。

from nltk.tokenize import word_tokenize
from nltk.stem.wordnet import WordNetLemmatizer

a = ["what are you doing","are you mad?","how sad"]
question =["what","why","how","are","am","should","do","can","have","could","when","whose","shall","is","would","may","whoever","does"];
word_list =["i","me","he","she","you","it","that","this","many","someone","everybody","her","they","them","his","we","am","is","are","was","were","should","did","would","does","do"];

def f(paragraph):
  sentences = paragraph.split(".")
  result = []

  for i in range(len(sentences)):

    token = word_tokenize(sentences[i])
    change_tense = [WordNetLemmatizer().lemmatize(word, 'v') for word in token]
    input_sentences = [item.lower() for item in change_tense]

    if input_sentences[-1]=='?':
        result.append("question")

    elif input_sentences[0] in question:
        find_question = [input_sentences.index(qestion) for qestion in input_sentences if qestion in question]
        if len(find_question) > 0:
            for a in find_question:
                if input_sentences[a + 1] in word_list:
                    result.append("question")
                else:
                    result.append("not a question")
    else:
        result.append("not a quetion")

return result
my_result = [f(paragraph) for paragraph in a]
print my_result

但它会出现以下错误。

if input_sentences[a + 1] in word_list:
IndexError: list index out of range

我认为找到 a 的下一个元素值的问题原因。谁能帮我解决这个问题。

Answer 1

问题是input_sentences.index(qestion) 可以返回input_sentences 的最后一个索引，这意味着a + 1 将比input_sentences 中的元素大一个，这会导致IndexError 在您尝试时访问if input_sentences[a + 1] in word_list: 中不存在的列表元素。

因此，您检查“下一个元素”的逻辑不正确，列表中的最后一个元素没有“下一个元素”。查看您的单词表，What should I do 之类的问题将失败，因为do 将被选为问题词，但之后没有任何内容（假设您去掉标点符号）。因此，您需要重新考虑检测问题的方式。