帮我写一些先用网络爬虫实时获取新闻数据,然后将爬取到的数据存放到数据库中,再用联邦学习协同过滤算法处理新闻数据的程序,给出相关代码及解释
时间: 2023-05-27 09:04:28 浏览: 96
以下是一个使用Python语言实现的示例程序,包含了网络爬虫、数据存储和联邦学习协同过滤算法:
爬虫:
```python
import requests
from bs4 import BeautifulSoup
# 定义抓取新闻的函数
def get_news(url):
# 发送请求获取页面内容
r = requests.get(url)
# 使用BeautifulSoup解析网页
soup = BeautifulSoup(r.content, 'html.parser')
# 获取新闻列表
news_list = soup.find_all('div', class_='news-item')
# 解析每条新闻的标题和链接
news_data = []
for news in news_list:
title = news.find('a').text.strip()
link = news.find('a')['href']
news_data.append({'title': title, 'link': link})
return news_data
# 抓取百度新闻首页的新闻
url = 'https://www.baidu.com/s?tn=news'
news_data = get_news(url)
# 输出抓取的新闻
print(news_data)
```
数据存储:
```python
import sqlite3
# 创建数据库
conn = sqlite3.connect('news.db')
# 创建新闻表
conn.execute('''CREATE TABLE NEWS
(ID INT PRIMARY KEY NOT NULL,
TITLE TEXT NOT NULL,
LINK TEXT NOT NULL);''')
# 将新闻数据存入数据库
for i, news in enumerate(news_data):
conn.execute(f"INSERT INTO NEWS (ID, TITLE, LINK) VALUES({i+1}, '{news['title']}', '{news['link']}')")
# 提交事务并关闭连接
conn.commit()
conn.close()
```
联邦学习协同过滤算法:
```python
import numpy as np
# 定义协同过滤算法中的相似度计算函数
def calc_similarity(u, v):
return np.dot(u, v) / (np.linalg.norm(u) * np.linalg.norm(v))
# 加载新闻数据
conn = sqlite3.connect('news.db')
cursor = conn.execute('SELECT * FROM NEWS')
news_data = cursor.fetchall()
cursor.close()
conn.close()
# 构建用户-新闻矩阵
user_news = np.zeros((100, len(news_data)))
for i in range(user_news.shape[0]):
# 随机选择一些新闻给每个用户标记
user_news[i, np.random.choice(user_news.shape[1], size=5, replace=False)] = 1
# 按照用户编号分组,每组执行一次联邦学习协同过滤算法
num_groups = 10
group_size = user_news.shape[0] // num_groups
for i in range(num_groups):
# 获取当前组的用户-新闻矩阵
start_idx = i * group_size
end_idx = (i + 1) * group_size
group_user_news = user_news[start_idx:end_idx]
# 计算用户-用户相似度矩阵
user_user_similarity = np.zeros((group_size, group_size))
for j in range(group_size):
for k in range(j + 1, group_size):
similarity = calc_similarity(group_user_news[j], group_user_news[k])
user_user_similarity[j, k] = similarity
user_user_similarity[k, j] = similarity
# 计算新闻-新闻相似度矩阵
news_news_similarity = np.zeros((user_news.shape[1], user_news.shape[1]))
for j in range(user_news.shape[1]):
for k in range(j + 1, user_news.shape[1]):
similarity = calc_similarity(user_news[:, j], user_news[:, k])
news_news_similarity[j, k] = similarity
news_news_similarity[k, j] = similarity
# 使用用户-用户相似度矩阵和新闻-新闻相似度矩阵,计算用户对每条新闻的兴趣度
for j in range(group_size):
for k in range(user_news.shape[1]):
if group_user_news[j, k] == 0:
group_user_news[j, k] = np.sum(user_user_similarity[j] * user_news[:, k] * news_news_similarity[k])
```
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