通过结束字符拆分句子答案

【问题标题】：Splitting a sentence by ending characters通过结束字符拆分句子
【发布时间】：2017-09-21 10:48:11
【问题描述】：

最近的一个项目让我需要将传入的短语（作为字符串）拆分为它们的组成句子。例如，这个字符串：

"Your mother was a hamster, and your father smelt of elderberries! Now go away, or I shall taunt you a second time. You know what, never mind. This entire sentence is far too silly. Wouldn't you agree? I think it is."

需要变成由以下元素组成的列表：

["Your mother was a hamster, and your father smelt of elderberries",
"Now go away, or I shall taunt you a second time",
"You know what, never mind",
"This entire sentence is far too silly",
"Wouldn't you agree",
"I think it is"]

对于此函数，“句子”是一个以!、? 或. 结尾的字符串。请注意，如上所示，应从输出中删除标点符号。

我有一个工作版本，但它很丑，前导和尾随空格，我不禁想到有更好的方法：

from functools import reduce

def split_sentences(st):
  if type(st) is not str:
    raise TypeError("Cannot split non-strings")
  sl = st.split('.')
  sl = [s.split('?') for s in sl]
  sl = reduce(lambda x, y: x+y, sl) #Flatten the list
  sl = [s.split('!') for s in sl]
  return reduce(lambda x, y: x+y, sl)

【问题讨论】：

标签： python arrays string list

【解决方案1】：

import re

st1 = "  Another example!! Let me contribute 0.50 cents here?? \
         How about pointer '.' character inside the sentence? \
         Uni Mechanical Pencil Kurutoga, Blue, 0.3mm (M310121P.33). \
         Maybe there could be a multipoint delimeter?.. Just maybe...  "

st2 = "One word"

def split_sentences(st):
    st = st.strip() + '. '
    sentences = re.split(r'[.?!][.?!\s]+', st)
    return sentences[:-1]

print(split_sentences(st1))
print(split_sentences(st2))

【讨论】：

【解决方案2】：

你也可以不使用正则表达式：

result = [s.strip() for s in String.replace('!', '.').replace('?', '.').split('.')]

或者，您可以编写一个不会大量复制数据的前沿算法：

String = list(String)

for i in range(len(String)):
    if (String[i] == '?') or (String[i] == '!'):
        String[i] = '.'

String = [s.strip() for s in String.split('.')]

【讨论】：

【解决方案3】：

改用re.split 来指定匹配任何句尾字符（以及任何后续空格）的正则表达式。

def split_sentences(st):
    sentences = re.split(r'[.?!]\s*', st)
    if sentences[-1]:
        return sentences
    else:
        return sentences[:-1]

【讨论】：

不错。如果您解释了 if-else，它可能会对 OP 有所帮助。
如果输入字符串的末尾有终止符，re.split 将返回一个末尾有一个空项的数组。空字符串是虚假的，因此如果数组 [-1] 的最后一项为空，则返回除最后一项之外的所有内容。

【解决方案4】：

您可以使用正则表达式split 将它们拆分为特定的特殊字符。

import re
str = "Your mother was a hamster, and your father smelt of elderberries! Now go away, or I shall taunt you a second time. You know what, never mind. This entire sentence is far too silly. Wouldn't you agree? I think it is."
re.compile(r'[?.!]\s+').split(str)

【讨论】：