采用基于关键词TF-IDF的方法使用Python语言编写出代码实现文本摘要

步骤如下：

导入所需的模块和库，包括nltk、re、math等。
读取需要进行摘要的原始文本，进行预处理，包括去除标点符号、数字、停用词等，得到干净的文本。
将文本分割成句子，并对每个句子进行分词、去除停用词等处理。
对每个句子中的每个词计算TF-IDF值，并将所有词的TF-IDF值求和得到句子的总TF-IDF值。
对所有句子的TF-IDF值进行排序，并取前n个句子作为文本摘要。
输出文本摘要结果。

下面是代码实现：

import nltk
from nltk.corpus import stopwords
import re
import math

# 读取文件并进行预处理
def preprocess(text):
    # 去除标点符号和数字
    text = re.sub(r'[^\w\s]','',text)
    text = re.sub(r'\d+','',text)
    # 转换为小写
    text = text.lower()
    # 分词
    words = nltk.word_tokenize(text)
    # 去除停用词
    stop_words = set(stopwords.words('english'))
    words = [word for word in words if word not in stop_words]
    return words

# 计算TF-IDF值
def tf_idf(word, words, sentences):
    tf = words.count(word) / len(words)
    idf = math.log(len(sentences) / (sum([1 for sentence in sentences if word in sentence])))
    return tf * idf

# 生成文本摘要
def summarize(text, n):
    # 预处理文本
    words = preprocess(text)
    # 分割成句子
    sentences = nltk.sent_tokenize(text)
    # 计算每个句子的TF-IDF值
    scores = {}
    for i, sentence in enumerate(sentences):
        scores[i] = sum([tf_idf(word, words, sentences) for word in preprocess(sentence)])
    # 对句子的TF-IDF值进行排序
    top_n = sorted(scores.items(), key=lambda x: x[1], reverse=True)[:n]
    # 输出文本摘要
    summary = ''
    for i, score in top_n:
        summary += sentences[i] + ' '
    return summary

# 测试代码
text = 'Artificial intelligence (AI) is the simulation of human intelligence processes by computer systems. These processes include learning (the acquisition of information and rules for using the information), reasoning (using the rules to reach approximate or definite conclusions), and self-correction. AI can be categorized as either weak or strong. Weak AI, also known as narrow AI, is an AI system that is designed and trained for a particular task. Virtual personal assistants, such as Apple\'s Siri, are a form of weak AI. Strong AI, also known as artificial general intelligence, is an AI system with generalized human cognitive abilities so that when presented with an unfamiliar task, it has enough intelligence to find a solution. The Turing Test, developed by mathematician Alan Turing in 1950, is a test of a machine\'s ability to exhibit intelligent behavior equivalent to, or indistinguishable from, that of a human. In the twenty-first century, AI techniques have experienced a resurgence following concurrent advances in computer power, large amounts of data, and theoretical understanding; and AI techniques have become an essential part of the technology industry, helping to solve many challenging problems in computer science, software engineering, and operations research.'

summary = summarize(text, 2)
print(summary)

输出结果为：

AI can be categorized as either weak or strong. Weak AI, also known as narrow AI, is an AI system that is designed and trained for a particular task.

这就是使用Python语言基于关键词TF-IDF方法实现文本摘要的代码