怎样在Python中提取网页元素？

import requests
from bs4 import BeautifulSoup

# 发送HTTP请求获取网页内容
url = "https://example.com"
response = requests.get(url)

# 使用BeautifulSoup解析HTML内容
soup = BeautifulSoup(response.text, 'html.parser')

# 提取特定元素，例如所有标题
titles = soup.find_all('h1')

# 打印提取的元素
for title in titles:
    print(title.text)

from selenium import webdriver

# 初始化浏览器驱动
driver = webdriver.Chrome(executable_path='/path/to/chromedriver')

# 打开网页
driver.get("https://example.com")

# 等待JavaScript加载完成
driver.implicitly_wait(10)

# 使用BeautifulSoup解析加载后的内容
soup = BeautifulSoup(driver.page_source, 'html.parser')

# 提取特定元素
titles = soup.find_all('h1')

# 关闭浏览器
driver.quit()

# 打印提取的元素
for title in titles:
    print(title.text)

# 使用CSS选择器
titles = soup.select('div.main-content h1')

# 使用XPath（需要安装lxml库）
from lxml import html
tree = html.fromstring(response.content)
titles = tree.xpath('//div[@class="main-content"]/h1/text()')

import aiohttp
import asyncio

async def fetch(session, url):
    async with session.get(url) as response:
        return await response.text()

async def main():
    async with aiohttp.ClientSession() as session:
        html = await fetch(session, "https://example.com")
        soup = BeautifulSoup(html, 'html.parser')
        titles = soup.find_all('h1')
        for title in titles:
            print(title.text)

asyncio.run(main())