计算单词列表之间的相似度

Question

我想计算两个单词列表之间的相似度，例如：

['email','user','this','email','address','customer']

类似于此列表：

['email','mail','address','netmail']

我希望获得比其他列表更高百分比的相似度，例如： ['address','ip','network'] 即使 address 存在于列表中。

Answer 1

由于您还没有真正能够演示水晶输出，这是我最好的镜头：

list_A = ['email','user','this','email','address','customer']
list_B = ['email','mail','address','netmail']

在上面的两个列表中，我们会发现列表中每个元素与其余元素的余弦相似度。即email 来自list_B 与list_A 中的每个元素：

def word2vec(word):
    from collections import Counter
    from math import sqrt

    # count the characters in word
    cw = Counter(word)
    # precomputes a set of the different characters
    sw = set(cw)
    # precomputes the "length" of the word vector
    lw = sqrt(sum(c*c for c in cw.values()))

    # return a tuple
    return cw, sw, lw

def cosdis(v1, v2):
    # which characters are common to the two words?
    common = v1[1].intersection(v2[1])
    # by definition of cosine distance we have
    return sum(v1[0][ch]*v2[0][ch] for ch in common)/v1[2]/v2[2]


list_A = ['email','user','this','email','address','customer']
list_B = ['email','mail','address','netmail']

threshold = 0.80     # if needed
for key in list_A:
    for word in list_B:
        try:
            # print(key)
            # print(word)
            res = cosdis(word2vec(word), word2vec(key))
            # print(res)
            print("The cosine similarity between : {} and : {} is: {}".format(word, key, res*100))
            # if res > threshold:
            #     print("Found a word with cosine distance > 80 : {} with original word: {}".format(word, key))
        except IndexError:
            pass

输出：

The cosine similarity between : email and : email is: 100.0
The cosine similarity between : mail and : email is: 89.44271909999159
The cosine similarity between : address and : email is: 26.967994498529684
The cosine similarity between : netmail and : email is: 84.51542547285166
The cosine similarity between : email and : user is: 22.360679774997898
The cosine similarity between : mail and : user is: 0.0
The cosine similarity between : address and : user is: 60.30226891555272
The cosine similarity between : netmail and : user is: 18.89822365046136
The cosine similarity between : email and : this is: 22.360679774997898
The cosine similarity between : mail and : this is: 25.0
The cosine similarity between : address and : this is: 30.15113445777636
The cosine similarity between : netmail and : this is: 37.79644730092272
The cosine similarity between : email and : email is: 100.0
The cosine similarity between : mail and : email is: 89.44271909999159
The cosine similarity between : address and : email is: 26.967994498529684
The cosine similarity between : netmail and : email is: 84.51542547285166
The cosine similarity between : email and : address is: 26.967994498529684
The cosine similarity between : mail and : address is: 15.07556722888818
The cosine similarity between : address and : address is: 100.0
The cosine similarity between : netmail and : address is: 22.79211529192759
The cosine similarity between : email and : customer is: 31.62277660168379
The cosine similarity between : mail and : customer is: 17.677669529663685
The cosine similarity between : address and : customer is: 42.640143271122085
The cosine similarity between : netmail and : customer is: 40.08918628686365

注意：我还在代码中注释了threshold 部分，以防万一 如果它们的相似度超过某个特定值，您只需要这些词 阈值，即 80%

编辑：

OP：但我真正想做的不是逐字比较，而是逐个列表

使用Counter 和math：

from collections import Counter
import math

counterA = Counter(list_A)
counterB = Counter(list_B)


def counter_cosine_similarity(c1, c2):
    terms = set(c1).union(c2)
    dotprod = sum(c1.get(k, 0) * c2.get(k, 0) for k in terms)
    magA = math.sqrt(sum(c1.get(k, 0)**2 for k in terms))
    magB = math.sqrt(sum(c2.get(k, 0)**2 for k in terms))
    return dotprod / (magA * magB)

print(counter_cosine_similarity(counterA, counterB) * 100)

输出：

53.03300858899106

Answer 2

您可以利用 Scikit-Learn（或其他 NLP）库的强大功能来完成此任务。下面的示例使用 CountVectorizer，但对于更复杂的文档分析，最好使用 TFIDF 矢量化器。

import numpy as np
from sklearn.feature_extraction.text import CountVectorizer, TfidfVectorizer
from sklearn.metrics.pairwise import cosine_similarity

def vect_cos(vect, test_list):
    """ Vectorise text and compute the cosine similarity """
    query_0 = vect.transform([' '.join(vect.get_feature_names())])
    query_1 = vect.transform(test_list)
    cos_sim = cosine_similarity(query_0.A, query_1.A)  # displays the resulting matrix
    return query_1, np.round(cos_sim.squeeze(), 3)

# Train the vectorizer
vocab=['email','user','this','email','address','customer']
vectoriser = CountVectorizer().fit(vocab)
vectoriser.vocabulary_ # show the word-matrix position pairs

# Analyse  list_1
list_1 = ['email','mail','address','netmail']
list_1_vect, list_1_cos = vect_cos(vectoriser, [' '.join(list_1)])

# Analyse list_2
list_2 = ['address','ip','network']
list_2_vect, list_2_cos = vect_cos(vectoriser, [' '.join(list_2)])

print('\nThe cosine similarity for the first list is {}.'.format(list_1_cos))
print('\nThe cosine similarity for the second list is {}.'.format(list_2_cos))

输出

The cosine similarity for the first list is 0.632.

The cosine similarity for the second list is 0.447.

编辑

如果您想计算“电子邮件”与任何其他字符串列表之间的余弦相似度，请使用“电子邮件”训练矢量化器，然后分析其他文档。

# Train the vectorizer
vocab=['email']
vectoriser = CountVectorizer().fit(vocab)

# Analyse  list_1
list_1 =['email','mail','address','netmail']
list_1_vect, list_1_cos = vect_cos(vectoriser, [' '.join(list_1)])
print('\nThe cosine similarity for the first list is {}.'.format(list_1_cos))

输出

The cosine similarity for the first list is 1.0.