python爬取知乎问答

要爬取知乎问答，可以通过以下步骤：

1. 安装 `requests` 和 `beautifulsoup4` 库：打开命令行，输入以下命令安装：

   pip install requests beautifulsoup4

2. 打开知乎网站，找到要爬取的问答页面，例如：https://www.zhihu.com/question/123456789。

3. 使用 `requests` 库获取该页面的 HTML 内容：

   import requests

   url = 'https://www.zhihu.com/question/123456789'
   headers = {
       'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3'}
   response = requests.get(url, headers=headers)
   html = response.text

4. 使用 `beautifulsoup4` 库解析 HTML 内容，获取问答的标题和内容：

   from bs4 import BeautifulSoup

   soup = BeautifulSoup(html, 'html.parser')
   title = soup.find('h1', class_='QuestionHeader-title').text.strip()
   content = soup.find('div', class_='QuestionRichText').text.strip()

5. 获取所有回答的内容：

   answers = []
   for answer in soup.find_all('div', class_='List-item'):
       answer_content = answer.find('div', class_='RichContent-inner').text.strip()
       answers.append(answer_content)

完整代码示例：

import requests
from bs4 import BeautifulSoup

url = 'https://www.zhihu.com/question/123456789'
headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3'}
response = requests.get(url, headers=headers)
html = response.text

soup = BeautifulSoup(html, 'html.parser')
title = soup.find('h1', class_='QuestionHeader-title').text.strip()
content = soup.find('div', class_='QuestionRichText').text.strip()

answers = []
for answer in soup.find_all('div', class_='List-item'):
    answer_content = answer.find('div', class_='RichContent-inner').text.strip()
    answers.append(answer_content)

print(title)
print(content)
print(answers)