Python3：爬取新浪、网易、今日头条、UC四大网站新闻标题及内容

以下是一个简单的Python3爬虫示例，可以爬取新浪、网易、今日头条和UC四个网站的新闻标题和内容：

import requests
from bs4 import BeautifulSoup

# 新浪新闻
sina_url = 'https://news.sina.com.cn/'
sina_res = requests.get(sina_url)
sina_res.encoding = 'utf-8'
sina_soup = BeautifulSoup(sina_res.text, 'html.parser')
sina_news = sina_soup.select('.news-item h2 a')
for news in sina_news:
    print(news.text, news['href'])

# 网易新闻
163_url = 'https://news.163.com/'
163_res = requests.get(163_url)
163_res.encoding = 'gbk'
163_soup = BeautifulSoup(163_res.text, 'html.parser')
163_news = 163_soup.select('.news_default a')
for news in 163_news:
    print(news.text, news['href'])

# 今日头条
toutiao_url = 'https://www.toutiao.com/'
toutiao_res = requests.get(toutiao_url)
toutiao_res.encoding = 'utf-8'
toutiao_soup = BeautifulSoup(toutiao_res.text, 'html.parser')
toutiao_news = toutiao_soup.select('.title-box a')
for news in toutiao_news:
    print(news.text, 'https://www.toutiao.com'+news['href'])

# UC头条
uc_url = 'https://www.uc.cn/'
uc_res = requests.get(uc_url)
uc_res.encoding = 'utf-8'
uc_soup = BeautifulSoup(uc_res.text, 'html.parser')
uc_news = uc_soup.select('.news-list a')
for news in uc_news:
    print(news.text, news['href'])

这个爬虫程序使用了requests库和BeautifulSoup库，它首先从每个网站获取HTML页面，然后使用BeautifulSoup从HTML中提取新闻标题和内容。在处理每个网站的HTML页面时，需要根据页面编码设置正确的编码方式，否则可能会出现乱码。