在句子列表中形成单词Bigrams并使用python计算bigrams

时间:2017-10-04 13:39:05

标签: python python-3.x list-comprehension word-frequency

我需要: 1.形成二元对并将它们存储在列表中 2.找到其中有最高频率的前3个二元组的id的总和

我有一个句子列表:

[['22574999', 'your message communication sent']
, ['22582857', 'your message be delivered']
, ['22585166', 'message has be delivered']
, ['22585424', 'message originated communication sent']]

这是我做的:

for row in messages: 
    sstrm = list(row)
    bigrams=[b for l in sstrm for b in zip(l.split(" ")[:1], l.split(" ")[1:])]
    print(sstrm[0],bigrams)

产生:

22574999 [('your', 'message')]
22582857 [('[your', 'message')]
22585166 [('message', 'has')]
22585424 [('message', 'originated')]

我想要的是:

22574999 [('your', 'message'),('communication','sent')]
22582857 [('[your', 'message'),('be','delivered')]
22585166 [('message', 'has'),('be','delivered')]
22585424 [('message', 'originated'),('communication','sent')]

我想得到以下结果 结果:

频率最高的前三名双子座:

('your', 'message') :2 
('communication','sent'):2    
('be','delivered'):2

最高频率排名前3位的双子座的身份总和:

('your', 'message'):2           Is included (22574999,22582857)     
('communication','sent'):2      Is included(22574999,22585424)
('be','delivered'):2            Is included (22582857,22585166)

感谢您的帮助!

2 个答案:

答案 0 :(得分:1)

首先我要指出的是, bigrams 是两个相邻元素的序列。

例如,狐狸跳过懒狗的大人物"是:

[("the", "fox"),("fox", "jumped"),("jumped", "over"),("over", "the"),("the", "lazy"),("lazy", "dog")]

可以使用 inverted index 对此问题进行建模,其中双字母组件是发布内容,而ids组是发布列表。

def bigrams(line):
    tokens = line.split(" ")
    return [(tokens[i], tokens[i+1]) for i in range(0, len(tokens)-1)]


if __name__ == "__main__":
    messages = [['22574999', 'your message communication sent'], ['22582857', 'your message be delivered'], ['22585166', 'message has be delivered'], ['22585424', 'message originated communication sent']]
    bigrams_set = set()

    for row in messages:
        l_bigrams = bigrams(row[1])
        for bigram in l_bigrams:
            bigrams_set.add(bigram)

    inverted_idx = dict((b,[]) for b in bigrams_set)

    for row in messages:
        l_bigrams = bigrams(row[1])
        for bigram in l_bigrams:
            inverted_idx[bigram].append(row[0])

    freq_bigrams = dict((b,len(ids)) for b,ids in inverted_idx.items())
    import operator
    top3_bigrams = sorted(freq_bigrams.iteritems(), key=operator.itemgetter(1), reverse=True)[:3]

输出

[(('communication', 'sent'), 2), (('your', 'message'), 2), (('be', 'delivered'), 2)]

虽然这段代码可以大量优化,但它可以为您提供理念。

答案 1 :(得分:0)

此行中有错误:

bigrams=[b for l in sstrm for b in zip(l.split(" ")[:1], l.split(" ")[1:])]

在zip的第一个参数中,您将使用[:1]停在列表的第一个元素。你想获得除最后一个元素之外的所有元素,它们对应于[:-1]

所以这条线应该是这样的:

bigrams=[b for l in sstrm for b in zip(l.split(" ")[:-1], l.split(" ")[1:])]