豆瓣影评信息爬取 （爬虫）

代码块：

from lxml import etree
import requests

headers={
    'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36 Edg/123.0.0.0'
}

url_list=[]
for i in range(0,5):
    i*=20
    urls=f"https://movie.douban.com/review/best/?start={i}"
    url_list.append(urls)
print(url_list)

detail_urls=[]
for url in url_list:
    response=requests.get(url,headers=headers)
    # print(response.status_code)
    content = response.content.decode('utf8')
    html=etree.HTML(content)
    detail_url = html.xpath('//div[@class="main-bd"]/h2/a/@href')
    detail_urls.append(detail_url)
    # print(detail_urls)
    # break

movies=[]
i=0
# 循环豆瓣网页的每一页
for page in detail_urls:
    # 循坏这页的网页每个连接
    for url in page:
        try:
            response=requests.get(url,headers=headers)
            content=response.content.decode('UTF-8')
            html=etree.HTML(content)
            # 抓取电影名
            # // *[ @ id = "content"] / div / div[2] / div[4] / div[2] / a
            title=html.xpath('//div[@class="subject-title"]/a/text()')[0][2:]
            # 抓取评论者和评分
            commenter=html.xpath('//header/a/span/text()')[0]
            rank=html.xpath('//heafer//span/@title')
            # 抓影评
            comment=html.xpath('//div[@id="link-report"]//p/text()')
            comment=''.join(comment)
            movie={
                "title":title,
                "commenter":commenter,
                # "rank":rank,
                # "comment":comment
            }
            movies.append(movie)
        except:
            continue
    i+=1
    print(f"第{i}页已经爬取完毕")

print(movies)

效果：

内容解释：

1. etree.HTML(内容)：将不是html的格式的内容转换成html

2. etree.tostring(内容，encoding=‘UTF-8’).decode(‘UTF-8’):如果不是UTF-8编码格式的内容，这里可以更改成UTF-8的内容

3. etree.parse(文件路径)：parse对html导入python并解析

4. 自定解析器：

   如果在浏览器上保存网页到本地，在python中获取.html文件需要利用自定解析器来解析文件内容

# 自定解析器
parser=etree.HTMLParser(encoding='UTF-8')
html=etree.parse(路径,parser=parser)
result=etree.tostring(html,encoding='UTF-8').decode('UTF-8')

xpath中的[1]表示第一个元素，而python中的第一个是从0开始,例如：[0]