python 爬虫 bs4 错误bs4.FeatureNotFound: Couldn‘t find a tree builder with the features you requested

今天孩子学习爬虫练习，遇到如下错误：

bs4.FeatureNotFound: Couldn't find a tree builder with the features you requested: lxml. Do you need to install a parser library?

    soup = bs4.BeautifulSoup(response.text, "lxml")
  File "E:\乐乐python\venv\lib\site-packages\bs4\__init__.py", line 251, in __init__
    % ",".join(features))
bs4.FeatureNotFound: Couldn't find a tree builder with the features you requested: lxml. Do you need to install a parser library?

代码如下：

# _*_ coding: UTF-8 _*_
# 开发团队： 信息化未来
# 开发人员： Administrator
# 开发时间：2022/9/3 12:01
# 文件名称： 网页新闻.py
# 开发工具: PyCharm

import requests, bs4, time
response = requests.get("https://icourse.xesimg.com/programme/static/py/pcdata/lw-web/新闻网站/index.html")
response.encoding = "UTF-8"
soup = bs4.BeautifulSoup(response.text, "lxml")
data1 = soup.find_all(name="div", attrs={'class': 'article'})

for n in data1:
    data2 = n.find_all(name="a")
    print("--------------------------------------")
    print("题目:"+data2[0].text)
    print("摘要:"+data2[1].text)
    print("主题:"+data2[2].text)

提示soup = bs4.BeautifulSoup(response.text, "lxml")这句有误，xlml修改为html.parser

如下

soup = bs4.BeautifulSoup(response.text, "html.parser")

运行结果：

 正常

原因：没有解析库安装包，还有第二种方法，不改原码，安装下html包就行了

pip install lxml

import requests, bs4, time
response = requests.get("https://icourse.xesimg.com/programme/static/py/pcdata/lw-web/新闻网站/index.html")
response.encoding = "UTF-8"
soup = bs4.BeautifulSoup(response.text, "lxml")
data1 = soup.find_all(name="div", attrs={'class': 'article'})

for n in data1:
    data2 = n.find_all(name="a")
    print("--------------------------------------")
    print("题目:"+data2[0].text)
    print("摘要:"+data2[1].text)
    print("主题:"+data2[2].text)

运行也正常