用python写了一个简单版本的textrank，实现提取关键词的功能。

import numpy as np import jieba import jieba.posseg as pseg class TextRank(object): def __init__(self, sentence, window, alpha, iternum): self.sentence = sentence self.window = window self.alpha = alpha self.edge_dict = {} #记录节点的边连接字典 self.iternum = iternum#迭代次数 #对句子进行分词 def cutSentence(self): jieba.load_userdict('user_dict.txt') tag_filter = ['a','d','n','v'] seg_result = pseg.cut(self.sentence) self.word_list = [s.word for s in seg_result if s.flag in tag_filter] print(self.word_list) #根据窗口，构建每个节点的相邻节点,返回边的集合 def createNodes(self): tmp_list = [] word_list_len = len(self.word_list) for index, word in enumerate(self.word_list): if word not in self.edge_dict.keys(): tmp_list.append(word) tmp_set = set() left = index - self.window + 1#窗口左边界 right = index + self.window#窗口右边界 if left < 0: left = 0 if right >= word_list_len: right = word_list_len for i in range(left, right): if i == index: continue tmp_set.add(self.word_list[i]) self.edge_dict[word] = tmp_set #根据边的相连关系，构建矩阵 def createMatrix(self): self.matrix = np.zeros([len(set(self.word_list)), len(set(self.word_list))]) self.word_index = {}#记录词的index self.index_dict = {}#记录节点index对应的词 for i, v in enumerate(set(self.word_list)): self.word_index[v] = i self.index_dict[i] = v for key in self.edge_dict.keys(): for w in self.edge_dict[key]: self.matrix[self.word_index[key]][self.word_index[w]] = 1 self.matrix[self.word_index[w]][self.word_index[key]] = 1 #归一化 for j in range(self.matrix.shape[1]): sum = 0 for i in range(self.matrix.shape[0]): sum += self.matrix[i][j] for i in range(self.matrix.shape[0]): self.matrix[i][j] /= sum #根据textrank公式计算权重 def calPR(self): self.PR = np.ones([len(set(self.word_list)), 1]) for i in range(self.iternum): self.PR = (1 - self.alpha) + self.alpha * np.dot(self.matrix, self.PR) #输出词和相应的权重 def printResult(self): word_pr = {} for i in range(len(self.PR)): word_pr[self.index_dict[i]] = self.PR[i][0] res = sorted(word_pr.items(), key = lambda x : x[1], reverse=True) print(res) if __name__ == '__main__': s = '程序员(英文Programmer)是从事程序开发、维护的专业人员。一般将程序员分为程序设计人员和程序编码人员，但两者的界限并不非常清楚，特别是在中国。软件从业人员分为初级程序员、高级程序员、系统分析员和项目经理四大类。' tr = TextRank(s, 3, 0.85, 700) tr.cutSentence() tr.createNodes() tr.createMatrix() tr.calPR() tr.printResult()

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