Frage: Bei Verwendung von SQL-Alchemie können Nicht-Primärschlüssel nicht auf automatische Inkrementierung eingestellt werden, aber ich möchte, dass dieser Nicht-Primärschlüssel nur als Index verwendet wird. Autoincrement=True ist ungültig. Wie kann man es automatisch erhöhen?
from sqlalchemy import String,Integer,Text,Column from sqlalchemy import create_engine from sqlalchemy.orm import sessionmaker from sqlalchemy.orm import scoped_session from sqlalchemy.ext.declarative import declarative_base engine=create_engine( "mysql+pymysql://root:root@127.0.0.1:3306/jdcrawl?charset=utf8", pool_size=200, max_overflow=300, echo=False ) BASE=declarative_base() # 实例化 class Goods(BASE): __tablename__='goods' id=Column(Integer(),primary_key=True,autoincrement=True) sku_id = Column(String(200), primary_key=True, autoincrement=False) name=Column(String(200)) price=Column(String(200)) comments_num=Column(Integer) shop=Column(String(200)) link=Column(String(200)) class Comments(BASE): __tablename__='comments' id=Column(Integer(),primary_key=True,autoincrement=True,nullable=False) sku_id=Column(String(200),primary_key=True,autoincrement=False) comments=Column(Text()) BASE.metadata.create_all(engine) Session=sessionmaker(engine) sess_db=scoped_session(Session)
Problem: Nach dem Crawlen einiger Seiten mit Kommentaren wird eine leere Seite angezeigt. Nach dem Hinzufügen einer Empfehlung ist es immer noch dasselbe. Probieren Sie die Lösung aus:
Ändern Sie den Thread-Pool Die Kommentare werden zu einem einzelnen Thread zusammengefasst und die Verzögerung wird für jede Seite mit erhaltenen Kommentaren um 1 Sekunde erhöht mehr als 2 Produkte gleichzeitig# 不能爬太快!!!不然获取不到评论 from bs4 import BeautifulSoup import requests from urllib import parse import csv,json,re import threadpool import time from jd_mysqldb import Goods,Comments,sess_db headers={ 'user-agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.198 Safari/537.36', 'Cookie': '__jdv=76161171|baidu|-|organic|%25E4%25BA%25AC%25E4%25B8%259C|1613711947911; __jdu=16137119479101182770449; areaId=7; ipLoc-djd=7-458-466-0; PCSYCityID=CN_410000_0_0; shshshfpa=07383463-032f-3f99-9d40-639cb57c6e28-1613711950; shshshfpb=u8S9UvxK66gfIbM1mUNrIOg%3D%3D; user-key=153f6b4d-0704-4e56-82b6-8646f3f0dad4; cn=0; shshshfp=9a88944b34cb0ff3631a0a95907b75eb; __jdc=122270672; 3AB9D23F7A4B3C9B=SEELVNXBPU7OAA3UX5JTKR5LQADM5YFJRKY23Z6HDBU4OT2NWYGX525CKFFVHTRDJ7Q5DJRMRZQIQJOW5GVBY43XVI; jwotest_product=99; __jda=122270672.16137119479101182770449.1613711948.1613738165.1613748918.4; JSESSIONID=C06EC8D2E9384D2628AE22B1A6F9F8FC.s1; shshshsID=ab2ca3143928b1b01f6c5b71a15fcebe_5_1613750374847; __jdb=122270672.5.16137119479101182770449|4.1613748918', 'Referer': 'https://www.jd.com/' } num=0 # 商品数量 comments_num=0 # 评论数量 # 获取商品信息和SkuId def getIndex(url): session=requests.Session() session.headers=headers global num res=session.get(url,headers=headers) print(res.status_code) res.encoding=res.apparent_encoding soup=BeautifulSoup(res.text,'lxml') items=soup.select('li.gl-item') for item in items[:3]: # 爬取3个商品测试 title=item.select_one('.p-name a em').text.strip().replace(' ','') price=item.select_one('.p-price strong').text.strip().replace('¥','') try: shop=item.select_one('.p-shopnum a').text.strip() # 获取书籍时查找店铺的方法 except: shop=item.select_one('.p-shop a').text.strip() # 获取其他商品时查找店铺的方法 link=parse.urljoin('https://',item.select_one('.p-img a').get('href')) SkuId=re.search('\d+',link).group() comments_num=getCommentsNum(SkuId,session) print(SkuId,title, price, shop, link, comments_num) print("开始存入数据库...") try: IntoGoods(SkuId,title, price, shop, link, comments_num) except Exception as e: print(e) sess_db.rollback() num += 1 print("正在获取评论...") # 获取评论总页数 url1 = f'https://club.jd.com/comment/productPageComments.action?productId={SkuId}&score=0&sortType=5&page=0&pageSize=10' headers['Referer'] = f'https://item.jd.com/{SkuId}.html' headers['Connection']='keep-alive' res2 = session.get(url1,headers=headers) res2.encoding = res2.apparent_encoding json_data = json.loads(res2.text) max_page = json_data['maxPage'] # 经测试最多可获取100页评论,每页10条 args = [] for i in range(0, max_page): # 使用此链接获取评论得到的为json格式 url2 = f'https://club.jd.com/comment/productPageComments.action?productId={SkuId}&score=0&sortType=5&page={i}&pageSize=10' # 使用此链接获取评论得到的非json格式,需要提取 # url2_2=f'https://club.jd.com/comment/productPageComments.action?callback=jQuery9287224&productId={SkuId}&score=0&sortType=5&page={i}&pageSize=10' args.append(([session,SkuId,url2], None)) pool2 = threadpool.ThreadPool(2) # 2个线程 reque2 = threadpool.makeRequests(getComments,args) # 创建任务 for r in reque2: pool2.putRequest(r) # 提交任务到线程池 pool2.wait() # 获取评论总数量 def getCommentsNum(SkuId,sess): headers['Referer']=f'https://item.jd.com/{SkuId}.html' url=f'https://club.jd.com/comment/productCommentSummaries.action?referenceIds={SkuId}' res=sess.get(url,headers=headers) try: res.encoding=res.apparent_encoding json_data=json.loads(res.text) # json格式转为字典 num=json_data['CommentsCount'][0]['CommentCount'] return num except: return 'Error' # 获取评论 def getComments(sess,SkuId,url2): global comments_num print(url2) headers['Referer'] = f'https://item.jd.com/{SkuId}.html' res2 = sess.get(url2,headers=headers) res2.encoding='gbk' json_data=res2.text ''' # 如果用url2_2需要进行如下操作提取json start = res2.text.find('jQuery9287224(') + len('jQuery9287224(') end = res2.text.find(');') json_data=res2.text[start:end] ''' dict_data = json.loads(json_data) try: comments=dict_data['comments'] for item in comments: comment=item['content'].replace('\n','') # print(comment) comments_num+=1 try: IntoComments(SkuId,comment) except Exception as e: print(e) sess_db.rollback() except: pass # 商品信息入库 def IntoGoods(SkuId,title, price, shop, link, comments_num): goods_data=Goods( sku_id=SkuId, name=title, price=price, comments_num=comments_num, shop=shop, link=link ) sess_db.add(goods_data) sess_db.commit() # 评论入库 def IntoComments(SkuId,comment): comments_data=Comments( sku_id=SkuId, comments=comment ) sess_db.add(comments_data) sess_db.commit() if __name__ == '__main__': start_time=time.time() urls=[] KEYWORD=parse.quote(input("请输入要查询的关键词:")) for i in range(1,2): # 爬取一页进行测试 url=f'https://search.jd.com/Search?keyword={KEYWORD}&wq={KEYWORD}&page={i}' urls.append(([url,],None)) # threadpool要求必须这样写 pool=threadpool.ThreadPool(2) # 2个线程的线程池 reque=threadpool.makeRequests(getIndex,urls) # 创建任务 for r in reque: pool.putRequest(r) # 向线程池提交任务 pool.wait() # 等待所有任务执行完毕 print("共获取{}件商品,获得{}条评论,耗时{}".format(num,comments_num,time.time()-start_time))
# 不能爬太快!!!不然获取不到评论 from bs4 import BeautifulSoup import requests from urllib import parse import csv,json,re import threadpool import time from jd_mysqldb import Goods,Comments,sess_db headers={ 'user-agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.198 Safari/537.36', 'Cookie': '__jdv=76161171|baidu|-|organic|%25E4%25BA%25AC%25E4%25B8%259C|1613711947911; __jdu=16137119479101182770449; areaId=7; ipLoc-djd=7-458-466-0; PCSYCityID=CN_410000_0_0; shshshfpa=07383463-032f-3f99-9d40-639cb57c6e28-1613711950; shshshfpb=u8S9UvxK66gfIbM1mUNrIOg%3D%3D; user-key=153f6b4d-0704-4e56-82b6-8646f3f0dad4; cn=0; shshshfp=9a88944b34cb0ff3631a0a95907b75eb; __jdc=122270672; 3AB9D23F7A4B3C9B=SEELVNXBPU7OAA3UX5JTKR5LQADM5YFJRKY23Z6HDBU4OT2NWYGX525CKFFVHTRDJ7Q5DJRMRZQIQJOW5GVBY43XVI; jwotest_product=99; __jda=122270672.16137119479101182770449.1613711948.1613738165.1613748918.4; JSESSIONID=C06EC8D2E9384D2628AE22B1A6F9F8FC.s1; shshshsID=ab2ca3143928b1b01f6c5b71a15fcebe_5_1613750374847; __jdb=122270672.5.16137119479101182770449|4.1613748918', 'Referer': 'https://www.jd.com/' } num=0 # 商品数量 comments_num=0 # 评论数量 # 获取商品信息和SkuId def getIndex(url): session=requests.Session() session.headers=headers global num res=session.get(url,headers=headers) print(res.status_code) res.encoding=res.apparent_encoding soup=BeautifulSoup(res.text,'lxml') items=soup.select('li.gl-item') for item in items[:2]: # 爬取2个商品测试 title=item.select_one('.p-name a em').text.strip().replace(' ','') price=item.select_one('.p-price strong').text.strip().replace('¥','') try: shop=item.select_one('.p-shopnum a').text.strip() # 获取书籍时查找店铺的方法 except: shop=item.select_one('.p-shop a').text.strip() # 获取其他商品时查找店铺的方法 link=parse.urljoin('https://',item.select_one('.p-img a').get('href')) SkuId=re.search('\d+',link).group() headers['Referer'] = f'https://item.jd.com/{SkuId}.html' headers['Connection'] = 'keep-alive' comments_num=getCommentsNum(SkuId,session) print(SkuId,title, price, shop, link, comments_num) print("开始将商品存入数据库...") try: IntoGoods(SkuId,title, price, shop, link, comments_num) except Exception as e: print(e) sess_db.rollback() num += 1 print("正在获取评论...") # 获取评论总页数 url1 = f'https://club.jd.com/comment/productPageComments.action?productId={SkuId}&score=0&sortType=5&page=0&pageSize=10' res2 = session.get(url1,headers=headers) res2.encoding = res2.apparent_encoding json_data = json.loads(res2.text) max_page = json_data['maxPage'] # 经测试最多可获取100页评论,每页10条 print("{}评论共{}页".format(SkuId,max_page)) if max_page==0: IntoComments(SkuId,'0') else: for i in range(0, max_page): # 使用此链接获取评论得到的为json格式 url2 = f'https://club.jd.com/comment/productPageComments.action?productId={SkuId}&score=0&sortType=5&page={i}&pageSize=10' # 使用此链接获取评论得到的非json格式,需要提取 # url2_2=f'https://club.jd.com/comment/productPageComments.action?callback=jQuery9287224&productId={SkuId}&score=0&sortType=5&page={i}&pageSize=10' print("开始获取第{}页评论:{}".format(i+1,url2) ) getComments(session,SkuId,url2) time.sleep(1) # 获取评论总数量 def getCommentsNum(SkuId,sess): url=f'https://club.jd.com/comment/productCommentSummaries.action?referenceIds={SkuId}' res=sess.get(url) try: res.encoding=res.apparent_encoding json_data=json.loads(res.text) # json格式转为字典 num=json_data['CommentsCount'][0]['CommentCount'] return num except: return 'Error' # 获取评论 def getComments(sess,SkuId,url2): global comments_num res2 = sess.get(url2) res2.encoding=res2.apparent_encoding json_data=res2.text ''' # 如果用url2_2需要进行如下操作提取json start = res2.text.find('jQuery9287224(') + len('jQuery9287224(') end = res2.text.find(');') json_data=res2.text[start:end] ''' dict_data = json.loads(json_data) comments=dict_data['comments'] for item in comments: comment=item['content'].replace('\n','') # print(comment) comments_num+=1 try: IntoComments(SkuId,comment) except Exception as e: print(e) sess_db.rollback() # 商品信息入库 def IntoGoods(SkuId,title, price, shop, link, comments_num): goods_data=Goods( sku_id=SkuId, name=title, price=price, comments_num=comments_num, shop=shop, link=link ) sess_db.add(goods_data) sess_db.commit() # 评论入库 def IntoComments(SkuId,comment): comments_data=Comments( sku_id=SkuId, comments=comment ) sess_db.add(comments_data) sess_db.commit() if __name__ == '__main__': start_time=time.time() urls=[] KEYWORD=parse.quote(input("请输入要查询的关键词:")) for i in range(1,2): # 爬取一页进行测试 url=f'https://search.jd.com/Search?keyword={KEYWORD}&wq={KEYWORD}&page={i}' urls.append(([url,],None)) # threadpool要求必须这样写 pool=threadpool.ThreadPool(2) # 2个线程的线程池 reque=threadpool.makeRequests(getIndex,urls) # 创建任务 for r in reque: pool.putRequest(r) # 向线程池提交任务 pool.wait() # 等待所有任务执行完毕 print("共获取{}件商品,获得{}条评论,耗时{}".format(num,comments_num,time.time()-start_time))
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