Python多線程豆瓣影評API接口爬蟲

爬蟲庫

使用簡單的requests庫，這是一個阻塞的庫，速度比較慢。
解析使用XPATH表達式
總體采用類的形式

多線程

使用concurrent.future并發模塊，建立線程池，把future對象扔進去執行即可實現并發爬取效果

數據存儲

使用Python ORM sqlalchemy保存到數據庫，也可以使用自帶的csv模塊存在CSV中。

API接口

因為API接口存在數據保護情況，一個電影的每一個分類只能抓取前25頁，全部評論、好評、中評、差評所有分類能爬100頁，每頁有20個數據，即最多為兩千條數據。

因為時效性原因，不保證代碼能爬到數據，只是給大家一個參考思路，上代碼：

from datetime import datetime
import random
import csv
from concurrent.futures import ThreadPoolExecutor, as_completedfrom lxml import etree
import pymysql
import requestsfrom models import create_session, Comments#隨機UA
USERAGENT = ['Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/14.0.835.163 Safari/535.1','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 Safari/537.36','Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0) Gecko/20100101 Firefox/6.0','Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/534.50 (KHTML, like Gecko) Version/5.1 Safari/534.50','Opera/9.80 (Windows NT 6.1; U; zh-cn) Presto/2.9.168 Version/11.50','Mozilla/5.0 (Windows; U; Windows NT 6.1; ) AppleWebKit/534.12 (KHTML, like Gecko) Maxthon/3.0 Safari/534.12'
]class CommentFetcher:headers = {'User-Agent': ''}cookie = ''cookies = {'cookie': cookie}# cookie為登錄后的cookie，需要自行復制base_node = '//div[@class="comment-item"]'def __init__(self, movie_id, start, type=''):''':type: 全部評論：''， 好評：h 中評：m 差評：l:movie_id: 影片的ID號:start: 開始的記錄數，0-480'''self.movie_id = movie_idself.start = startself.type = typeself.url = 'https://movie.douban.com/subject/{id}/comments?start={start}&limit=20&sort=new_score\&status=P&percent_type={type}&comments_only=1'.format(id=str(self.movie_id),start=str(self.start),type=self.type)#創建數據庫連接self.session = create_session()#隨機useragentdef _random_UA(self):self.headers['User-Agent'] = random.choice(USERAGENT)#獲取api接口，使用get方法，返回的數據為json數據，需要提取里面的HTMLdef _get(self):self._random_UA()res = ''try:res = requests.get(self.url, cookies=self.cookies, headers=self.headers)res = res.json()['html']except Exception as e:print('IP被封，請使用代理IP')print('正在獲取{} 開始的記錄'.format(self.start))return resdef _parse(self):res = self._get()dom = etree.HTML(res)#id號self.id = dom.xpath(self.base_node + '/@data-cid')#用戶名self.username = dom.xpath(self.base_node + '/div[@class="avatar"]/a/@title')#用戶連接self.user_center = dom.xpath(self.base_node + '/div[@class="avatar"]/a/@href')#點贊數self.vote = dom.xpath(self.base_node + '//span[@class="votes"]/text()')#星級self.star = dom.xpath(self.base_node + '//span[contains(@class,"rating")]/@title')#發表時間self.time = dom.xpath(self.base_node + '//span[@class="comment-time "]/@title')#評論內容 所有span標簽class名為short的節點文本self.content = dom.xpath(self.base_node + '//span[@class="short"]/text()')#保存到數據庫def save_to_database(self):self._parse()for i in range(len(self.id)):try:comment = Comments(id=int(self.id[i]),username=self.username[i],user_center=self.user_center[i],vote=int(self.vote[i]),star=self.star[i],time=datetime.strptime(self.time[i], '%Y-%m-%d %H:%M:%S'),content=self.content[i])self.session.add(comment)self.session.commit()return 'finish'except pymysql.err.IntegrityError as e:print('數據重復，不做任何處理')except Exception as e:#數據添加錯誤，回滾self.session.rollback()finally:#關閉數據庫連接self.session.close()#保存到csvdef save_to_csv(self):self._parse()f = open('comment.csv', 'w', encoding='utf-8')csv_in = csv.writer(f, dialect='excel')for i in range(len(self.id)):csv_in.writerow([int(self.id[i]),self.username[i],self.user_center[i],int(self.vote[i]),self.time[i],self.content[i]])f.close()if __name__ == '__main__':with ThreadPoolExecutor(max_workers=4) as executor:futures = []for i in ['', 'h', 'm', 'l']:for j in range(25):fetcher = CommentFetcher(movie_id=26266893, start=j * 20, type=i)futures.append(executor.submit(fetcher.save_to_csv))for f in as_completed(futures):try:res = f.done()if res:ret_data = f.result()if ret_data == 'finish':print('{} 成功保存數據'.format(str(f)))except Exception as e:f.cancel()