Python 字符串匹配 - 查找单词列表中的特定数量的单词是否存在于另一个列表中的句子中

Question

I have a String and a list defined as below

my_string = 'she said he replied'
my_list = ['This is a cool sentence', 'This is another sentence','she said hello he replied goodbye', 'she replied', 'Some more sentences in here', 'et cetera et cetera...']

I am trying to check if at least 3 words in my_string exists in any of the strings in my_list . The approach i'm taking is to split my_string , and use all to do the matching. However, this only works if all the items in my_string exist in a sentence from my_list

if all(word in item for item in my_list for word in my_string.split()):
    print('we happy')

1- How can I make it so the condition is satisfied if at least 3 items of my_string are present in the sentence list?

2- Is it possible to match only the first and last word in my_string in the same order? ie "she" and "replied" are present in 'she replied' at index 3 of my_list , return True.

Answer 1

The words in common between two strings can be computed using a set intersection. The len of the resulting set gives you the number of words the strings have in common.

First build a set of all words in the strings in my_list , using a set union:

all_words = set.union(*[set(item.split()) for item in my_list])

Then check if the intersection has length >= 3 :

search_words = set(my_string.split())
if len(search_words & all_words) >= 3:
    print('we happy')

Answer 2

Regarding part 1, I think this should work, and I would recommend using a regex and not string.split for finding words.You could also use nltk.word_tokenize if your sentences have complex words and punctuation. They are both slower than string.split, but if you need them, they're useful.

Here's a couple decent posts highlighting the differences (wordpunct-tokenize is basically a word regex in disguise):

nltk wordpunct_tokenize vs word_tokenize

Python re.split() vs nltk word_tokenize and sent_tokenize

import re

num_matches = 3

def get_words(input):
    return re.compile('\w+').findall(input)

my_string = 'she said he replied'
my_list = ['This is a cool sentence', 'This is another sentence','she said hello he replied goodbye', 'she replied', 'Some more sentences in here', 'et cetera et cetera...']

my_string_word_set = set(get_words(my_string))
my_list_words_set = [set(get_words(x)) for x in my_list]

result = [len(my_string_word_set.intersection(x)) >= num_matches for x in my_list_words_set]
print(result)

Results in

[False, False, True, False, False, False]

For part 2, something like this should work, though it's not a super clean solution. If you don't want them just in order, but next to each other, check that the indexes are 1 apart instead.

words = get_words(my_string)
first_and_last = [words[0], words[-1]]
my_list_dicts = []
for sentence in my_list:
    word_dict = {}
    sentence_words = get_words(sentence)
    for i, word in enumerate(sentence_words):
        word_dict[word] = i
    my_list_dicts.append(word_dict)

result2 = []
for word_dict in my_list_dicts:
    if all(k in word_dict for k in first_and_last) and word_dict[first_and_last[0]] < word_dict[first_and_last[1]]:
        result2.append(True)
    else:
        result2.append(False)

print(result2)

Result:

[False, False, True, True, False, False]

Answer 3

Use the inherent coding that True is 1, False is 0. Sum the values of the in results:

if sum(word in item for item in my_list for word in my_string.split()) >= 3:
    print('we happy')

For your given input, this prints we happy .

Re: mamun 's point, we also want to make sure that whole words match. You'll need to split each string in my_list to get the list of available words. kaya3 already posted what I would tell you to do.

Answer 4

you can use flashtext as well for doing this

from flashtext import KeywordProcessor

kw_list = my_string.split()
kp = KeywordProcessor()
kp.add_keywords_from_list(kw_list) # add keyword that you are looking for 

def func_(x):
    kw = kp.extract_keywords(x)  # this will return all keyword present in the string
    return len(set(kw)) # now you find the sum of unique kw found in string 

print(list(map(func_, my_list)))
[0, 0, 4, 2, 0, 0]