提取搜索词周围的单词

时间:2013-07-15 01:56:40

标签: python regex find text-processing

我有这个脚本在文本中进行单词搜索。搜索结果非常好,结果按预期工作。我想要实现的是提取接近匹配的n个单词。例如:

  

世界是一个小地方,我们应该尽力照顾它。

假设我正在寻找place,我需要提取右侧的3个单词和左侧的3个单词。在这种情况下,他们将是:

left -> [is, a, small]
right -> [we, should, try]

这样做的最佳方法是什么?

谢谢!

5 个答案:

答案 0 :(得分:14)

def search(text,n):
    '''Searches for text, and retrieves n words either side of the text, which are retuned seperatly'''
    word = r"\W*([\w]+)"
    groups = re.search(r'{}\W*{}{}'.format(word*n,'place',word*n), text).groups()
    return groups[:n],groups[n:]

这允许您指定要捕获的任意一侧的单词数。它通过动态构造正则表达式来工作。随着

t = "The world is a small place, we should try to take care of it."
search(t,3)
(('is', 'a', 'small'), ('we', 'should', 'try'))

答案 1 :(得分:3)

找到所有单词:

import re

sentence = 'The world is a small place, we should try to take care of it.'
words = re.findall(r'\w+', sentence)

获取您正在寻找的单词的索引:

index = words.index('place')

然后使用切片找到其他的:

left = words[index - 3:index]
right = words[index + 1:index + 4]

答案 2 :(得分:3)

虽然正则表达式可行,但我认为这个问题太过分了。你最好有两个列表理解:

sentence = 'The world is a small place, we should try to take care of it.'.split()
indices = (i for i,word in enumerate(sentence) if word=="place")
neighbors = []
for ind in indices:
    neighbors.append(sentence[ind-3:ind]+sentence[ind+1:ind+4])

请注意,如果您要查找的单词在句子中连续出现多次,则此算法将包含连续出现的邻居。
例如:

在[29]中:邻居= []

在[30]中:句子='世界是一个小地方的地方,我们应该尝试照顾它。'。split()

在[31]中:句子 出[31]: [ '的',  '世界',  “是”,  '一个',  '小',  '地点',  '地点',  '地点,',  '我们',  '应该',  '尝试',  '至',  '采取',  '关心',  '的',  '它。']

In [32]: indices = [i for i,word in enumerate(sentence) if word == 'place']

In [33]: for ind in indices:
   ....:     neighbors.append(sentence[ind-3:ind]+sentence[ind+1:ind+4])


In [34]: neighbors
Out[34]: 
[['is', 'a', 'small', 'place', 'place,', 'we'],
 ['a', 'small', 'place', 'place,', 'we', 'should']]

答案 3 :(得分:3)

import re
s='The world is a small place, we should try to take care of it.'
m = re.search(r'((?:\w+\W+){,3})(place)\W+((?:\w+\W+){,3})', s)
if m:
    l = [ x.strip().split() for x in m.groups()]
left, right = l[0], l[2]
print left, right

输出

['is', 'a', 'small'] ['we', 'should', 'try']

如果您搜索The,则会产生:

[] ['world', 'is', 'a']

答案 4 :(得分:3)

处理搜索关键字多次出现的场景。例如下面是搜索关键字:地方出现3次

的输入文本
The world is a small place, we should try to take care of this small place by planting trees in every place wherever is possible

这是函数

import re

def extract_surround_words(text, keyword, n):
    '''
    text : input text
    keyword : the search keyword we are looking
    n : number of words around the keyword
    '''
    #extracting all the words from text
    words = words = re.findall(r'\w+', text)
    
    #iterate through all the words
    for index, word in enumerate(words):

        #check if search keyword matches
        if word == keyword:
            #fetch left side words
            left_side_words = words[index-n : index]
            
            #fetch right side words
            right_side_words = words[index+1 : index + n + 1]
            
            print(left_side_words, right_side_words)

调用函数

text = 'The world is a small place, we should try to take care of this small place by planting trees in every place wherever is possible'
keyword = "place"
n = 3
extract_surround_words(text, keyword, n)

output : 
['is', 'a', 'small'] ['we', 'should', 'try']
['we', 'should', 'try'] ['to', 'microsot', 'is']
['also', 'take', 'care'] ['googe', 'is', 'one']