项目：豆瓣电影Top250的爬取
案例需求：
1.使用scrapy爬虫技术爬取豆瓣电影Top250的电影数据（包括排名、电影名称、导演、演员、url、评分）
2.实现分页爬取，共十页
3.将爬取下来的数据保存在数据库中
案例分析：
1.找到正确的数据吧，并复制正确的请求url
做好准备：开启管道、关闭君子协议、伪造浏览器
ITEM_PIPELINES = {'doubanbook.pipelines.DoubanbookPipeline': 300,
}
ROBOTSTXT_OBEY = False
USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/106.0.0.0 Safari/537.36'
2.解析数据：如title
def parse(self, response):# 实例一个容器保存爬取的信息item = DoubanbookItem()# 这部分是爬取部分，使用xpath的方式选择信息，具体方法根据网页结构而定for box in response.xpath('//ol[@class="grid_view"]/li'):item['Rank'] = box.xpath('.//div[@class="pic"]/em/text()').extract()[0]item['Name'] = box.xpath('.//div[@class="info"]/div[1]/a/span[1]/text()').extract()[0].strip().replace("\n","").replace(" ", "")s = box.xpath('.//div[@class="bd"]/p/text()').extract()[0].strip().replace(" ", "")item['Author'] = s.split()[0]if len(s.split()) > 1:item['Actor'] = s.split()[1]item['Score'] = box.xpath('.//div[@class="star"]/span[2]/text()').extract()[0].strip()item['Url'] = box.xpath('.//div[@class="pic"]/a/@href').extract()yield itemitems.py中
import scrapyclass DoubanbookItem(scrapy.Item):# define the fields for your item here like:# name = scrapy.Field()Rank = scrapy.Field()Name = scrapy.Field()Author = scrapy.Field()Actor = scrapy.Field()Score = scrapy.Field()Url = scrapy.Field()3.获取翻页链接
# 获取下一页的rl信息next_url = response.xpath('//span[@class="next"]/link/@href').extract()if next_url:# 将信息组合成下一页的urlpage = 'https://movie.douban.com/top250' + next_url[0]yield scrapy.Request(page, callback=self.parse)
4.保存至数据库
pipelines.py
from itemadapter import ItemAdapter
import pymysql.cursors
import pymysql
from twisted.enterprise import adbapiclass DoubanbookPipeline(object):def __init__(self):# 打开文件# 连接数据库self.conn = pymysql.connect(host='localhost',port=3306,user='root',passwd='wx990826',db='douban',)self.cur = self.conn.cursor()def process_item(self, item, spider):sqli = "insert into movie(ranks,title,author,actor,score,url) values(%s,%s,%s,%s,%s,%s)"self.cur.execute(sqli, (item['Rank'], item['Name'], item['Author'], item['Actor'], item['Score'],item['Url']))self.conn.commit()return item# 该方法在spider被开启时被调用。运行项目：
start.py
from scrapy import cmdline cmdline.execute(['scrapy','crawl','read','--nolog'])
运行结果：
