python + request + lxml的几个例证
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python + request + lxml的几个例子
例子没有加入失败后重做的功能，这个也可以考虑增加。
第三个例子加入了访问频率控制
遍历图片的例子加入多线程，明显爬得快很多
解析163新闻列表的例子：
#!/usr/bin/python# encoding=gbk# 我只是尝试遍历新闻而已，只有有很多链接博客，主题之类的没有操作# 如果要实现，就自己判断url来分析到底是什么，然后做相应的处理import sysimport requestsimport datetimeimport timeimport MySQLdbimport chardetimport lxml.html.soupparser as soupparserimport lxml.etree as etreestart_datetime = datetime.datetime.now()def parseFromWin1252(str): # 因为新闻有一些是乱码，编码是windows-1252，需要转换成GBK #print len(tt.decode("ISO-8859-1").encode("windows-1252").decode("GBK")) #print len(tt) try: return str.encode("windows-1252").decode("GBK") except UnicodeEncodeError: #print "UnicodeEncodeError" return str except UnicodeDecodeError: #print "UnicodeDecodeError" return strdef resolveAndSaveNewContentFromLink(link, linkTitle, cursor): # 打开一个链接，并得到里面的内容 # 有两种情况无法得到，1.没有标题的，可能是一个主题的页面；2.报异常的，还没处理，所以无法拿到内容 print u"处理:", link request = requests.get(link) try: dom = soupparser.fromstring(request.content) body = dom[0] titles = body.xpath("//h1[@id='h1title']") if len(titles) > 0: #有标题 title = parseFromWin1252(titles[0].text) print u"@TITLE:", request.encoding, title, link newContents = body.xpath("//div[@id='endText']//p") alist = [] for content in newContents: if content.text != None: alist.append(content.text) text = parseFromWin1252("
遍历糗事百科的文章，只遍历导航上面的几个分类，热门，最新，等等
#!/usr/bin/ScanningQiuShiBaiKe.py# encoding=gbkimport sysimport osimport MySQLdbimport requestsimport datetimeimport timeimport lxml.html.soupparser as soupparserimport lxml.etree as etreecurrentPageId = "currentPageId"def getImageFile(imgUrl): #文件下载，并写入本地硬盘，返回文件名 local_filename = imgUrl.split('/')[-1] local_filename= "/home/pandy/tmp/"+local_filename print u"下载文件成功: ", local_filename r = requests.get(imgUrl, stream=True) # here we need to set stream = True parameter with open(local_filename, 'wb') as f: for chunk in r.iter_content(chunk_size=1024): if chunk: # filter out keep-alive new chunks f.write(chunk) f.flush() f.close() return local_filename return Nonedef scannintArticle(cursor, type, url, article): #处理一个主题的信息 articleStr = etree.tostring(article) articleBody = soupparser.fromstring(articleStr) details = articleBody.xpath("//div[@class='detail']") authors = articleBody.xpath("//div[@class='author']") contents = articleBody.xpath("//div[@class='content']") thumbs = articleBody.xpath("//div[@class='thumb']") values = [type, url] if len(details) > 0: detailStr = etree.tostring(details[0]) detail = soupparser.fromstring(detailStr) values.append(detail.xpath("//a")[0].text) values.append(detail.xpath("//a")[0].get("href")) else: values.append("") values.append("") if len(authors) > 0: authorStr = etree.tostring(authors[0]) author = soupparser.fromstring(authorStr) values.append(author.xpath("//a")[0].text) values.append(author.xpath("//a")[0].get("href")) else: values.append("") values.append("") if len(contents) > 0: contentStr = etree.tostring(contents[0]) values.append(contents[0].text) else: values.append("") values.append("") if len(thumbs) > 0: thumbStr = etree.tostring(thumbs[0]) thumb = soupparser.fromstring(thumbStr) imgUrl = thumb.xpath("//img")[0].get("src") values.append(imgUrl) #下载图片，先临时存放，然后在读取出来保存到数据库，并删除 local_filename = getImageFile(imgUrl) f = open( local_filename , "rb" ) b = f.read() f.close() os.remove(local_filename) values.append(MySQLdb.Binary(b)) else: values.append("") values.append(None) values.append("Success") print values cursor.execute( "INSERT INTO qs_article ( type, url, detial_link, detail, user_link, user, content,img, img_content,status) VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)", values)def scanning4typeArticle(cursor, type, url): #扫描一页 request = requests.get(url) #print request.encoding print url #print len(request.content) #print request.content try: dom = soupparser.fromstring(request.content) body = dom[1] #查找一页下面的主题 articleList = body.xpath("//div[@class='block untagged mb15 bs2']") for article in articleList: scannintArticle(cursor, type, url, article) except: print "Error" values = [type, url, '', '', '', '', '', '',None, "Error"] cursor.execute( "INSERT INTO qs_article ( type, url, detial_link, detail, user_link, user, content,img, img_content, status) VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)", values)def scanning4type(cursor, type, url, subfix): #得到分页数，然后一页一页的打开 print u"开始扫描文章" request = requests.get(url); dom = soupparser.fromstring(request.content) body = dom[0] #得到底部分页的最大值 pagebars = body.xpath("//div[@class='pagebar']/a") if len(pagebars) > 2: maxPageSize = int(pagebars[len(pagebars) - 2].text) + 1 #一页一页的打开 for i in range(1, maxPageSize): scanningUrl = "".join([url, subfix]).replace(currentPageId, str(i)) scanning4typeArticle(cursor, type, scanningUrl) print u"扫描文章完成"def main(): # 主方法 #打开数据库 conn = MySQLdb.connect(host="192.168.0.196", user="root", passwd="", db="python", charset="utf8") cursor = conn.cursor() cursor.execute("delete from qs_article") #扫描几个类型，就是导航的前几个分类 scanning4type(cursor, "8HR", "", "".join(["/page/", "currentPageId", " s=4602020"])) #scanning4type(cursor, "HOT", "", "".join(["/page/", "currentPageId", " s=4602057"])) #scanning4type(cursor, "IMGRANK", "", "".join(["/page/", "currentPageId", " s=4602057"])) #scanning4type(cursor, "LATE", "", "".join(["/page/", "currentPageId", " s=4602057"])) #scanning4typeArticle(cursor, type, "") #关闭数据库 cursor.close() conn.close()#开始运行主程序main()
遍历新浪一些博客的图片,加入了访问频率控制
#!/usr/bin/python# encoding=gbk# tag=%E7%BE%8E%E5%A5%B3&page=3&type=2&blogid=67f899b332002zdw&ch=import sysimport osimport requestsimport MySQLdbimport lxml.html.soupparser as soupparserimport lxml.etree as etreeimport jsonimport timemaxPage = 100 # 定义被扫描的最大页数requests.adapters.DEFAULT_RETRIES = 5#加入控制打开频率DEFAULT_OPEN_PAGE_FREQUENCY = 1 #打开页面的间隔事件DEFAULT_OPEN_IMAGE_FREQUENCY = 3 #打开图片页面的间隔事件DEFAULT_IMAGE_COUNT = 0 #图片计数器DEFAULT_IMAGE_SIZE = 20 #打开size张图片后，要sleep DEFAULT_OPEN_IMAGE_FREQUENCY秒钟def saveImage(title, imageSrc): # 保存图片 if title == None: title = u"无题" print u"标题:%s 图片:%s" % (title, imageSrc) dirStr = u"/mnt/E/新浪图集/" + title + "/" if not os.path.exists(dirStr): os.makedirs(dirStr) fileName = imageSrc.split('/')[-1] request = requests.get(imageSrc, stream=True) with open(dirStr + fileName, "wb") as file: for chunk in request.iter_content(chunk_size=1024): if chunk: # filter out keep-alive new chunks 5 file.write(chunk) file.flush() file.close()def listPicPage(pageUrl): #从首页打开链接，然后进行图片的页面 global DEFAULT_IMAGE_COUNT request = requests.get(pageUrl) dom = soupparser.fromstring(request.content) body = dom[1] title = body.xpath("//h3[@class='title']") titleStr = ""; if len(title) > 0: titleStr = title[0].text imageList = body.xpath("//div[@class='imgArea']/img[@class='qImg']") print u"遍历图片页面， 标题:%s, 地址: %s " % (titleStr, pageUrl) imageSrc = None for image in imageList: # 这里好像有两个地址，先用real_src，否在用src if image.get("real_src") != None: imageSrc = image.get("real_src") else: imageSrc = image.get("src") #要存在图片地址，才需要继续解析 if imageSrc != None: saveImage(titleStr, imageSrc) #访问频率控制 DEFAULT_IMAGE_COUNT = DEFAULT_IMAGE_COUNT + 1 if DEFAULT_IMAGE_COUNT % DEFAULT_IMAGE_SIZE == 0: print u"图片计数:%s, 休息 %s 秒钟后继续\n" % (DEFAULT_IMAGE_COUNT, DEFAULT_OPEN_IMAGE_FREQUENCY) time.sleep(DEFAULT_OPEN_IMAGE_FREQUENCY)def listPicIndex(): #遍历首页 # 根据页数来打开url for i in range(1, maxPage + 1): url = " tag=%E7%BE%8E%E5%A5%B3&page=" + str( i) + "&type=2&blogid=67f899b332002zdw&ch=" request = requests.get(url) json_obj = json.loads(request.content) for item in json_obj["data"]["list"]: #找到这一页的所有图片链接，然后进行打开这个链接，才是显示图片的页面 dom = soupparser.fromstring(item) link = dom.xpath("//a[@class='pic']") if len(link) > 0: #遍历图片的页面 listPicPage(link[0].get("href")) print u"---------------------------------------------完成一个图片链接, 页数:", i #访问频率控制 # time.sleep(DEFAULT_OPEN_PAGE_FREQUENCY) print u"---------------------------------------------完成页数", maxPage, ":", idef main(): listPicIndex() #listPicPage("")if __name__ == "__main__": main()
上面的例子改成多线程
#!/usr/bin/python# encoding=gbk# tag=%E7%BE%8E%E5%A5%B3&page=3&type=2&blogid=67f899b332002zdw&ch=import sysimport osimport requestsimport MySQLdbimport lxml.html.soupparser as soupparserimport lxml.etree as etreeimport jsonimport timeimport threadingMAX_PAGE = 100 # 定义被扫描的最大页数MAX_ERROR = 10 # 定义线程允许出现的最大错误数，当不超过这个数字的时候，会自动继续重试PAGE_SIZE = 5 #段数DEFAULT_OPEN_PAGE_FREQUENCY = 2 #完成一页休眠的时间DEFAULT_OPEN_PAGE_ERROR_WAIT_FREQUENCY = 5 #出现异常之后等待重试的事件requests.adapters.DEFAULT_RETRIES = 5def saveImage(thName, title, imageSrc, currentPath): # 保存图片 if title == None: title = u"无题" print u"线程名称:%s, 页码:%s, 标题:%s 图片:%s" % (thName, currentPath, title, imageSrc) dirStr = u"/mnt/E/新浪图集/" + title + "/" if not os.path.exists(dirStr): os.makedirs(dirStr) fileName = imageSrc.split('/')[-1] request = requests.get(imageSrc, stream=True) with open(dirStr + fileName, "wb") as file: for chunk in request.iter_content(chunk_size=1024): if chunk: # filter out keep-alive new chunks 5 file.write(chunk) file.flush() file.close()def listPicPage(thName, pageUrl, currentPath): #从首页打开链接，然后进行图片的页面 global DEFAULT_IMAGE_COUNT request = requests.get(pageUrl) dom = soupparser.fromstring(request.content) body = dom[1] title = body.xpath("//h3[@class='title']") titleStr = ""; if len(title) > 0: titleStr = title[0].text imageList = body.xpath("//div[@class='imgArea']/img[@class='qImg']") #print u"\n\n页码:%s, 遍历图片页面， 标题:%s, 地址: %s " % (currentPath, titleStr, pageUrl) imageSrc = None for image in imageList: # 这里好像有两个地址，先用real_src，否在用src if image.get("real_src") != None: imageSrc = image.get("real_src") else: imageSrc = image.get("src") #要存在图片地址，才需要继续解析 if imageSrc != None: saveImage(thName, titleStr, imageSrc, currentPath)def listPicIndex(thName, startPath, endPath): #遍历首页 # 根据页数来打开url for i in range(startPath, endPath + 1): url = " tag=%E7%BE%8E%E5%A5%B3&page=" + str( i) + "&type=2&blogid=67f899b332002zdw&ch=" print url request = requests.get(url) json_obj = json.loads(request.content) error_count = 0 for item in json_obj["data"]["list"]: #找到这一页的所有图片链接，然后进行打开这个链接，才是显示图片的页面 dom = soupparser.fromstring(item) link = dom.xpath("//a[@class='pic']") if len(link) > 0: #遍历图片的页面 try: listPicPage(thName, link[0].get("href"), i) except: if error_count < MAX_ERROR: error_count = error_count + 1 #错先错误的话，等待一会儿，再重试 print u"---------------------------------------------休眠%s秒钟后重试, 页数:%s" % ( DEFAULT_OPEN_PAGE_ERROR_WAIT_FREQUENCY, i) time.sleep(DEFAULT_OPEN_PAGE_ERROR_WAIT_FREQUENCY) listPicPage(thName, link[0].get("href"), i) else: print u"出错超过预设次数，退出爬虫。" #print u"---------------------------------------------完成一个图片链接, 页数:", i #访问频率控制 time.sleep(DEFAULT_OPEN_PAGE_FREQUENCY) print u"---------------------------------------------完成页数", MAX_PAGE, ":", i return Trueclass MyThread(threading.Thread): def __init__(self, name, startPath, endPage): threading.Thread.__init__(self) self.name = name self.is_stop = False self.startPage = startPath self.endPage = endPage def run(self): while not self.is_stop: #遍历完成后停止线程 self.is_stop = listPicIndex(self.name, self.startPage, self.endPage) def stop(self): #手动设置停止标记 self.is_stop = Trueif __name__ == "__main__": #分段创建线程 count=1; for i in range(1, MAX_PAGE, PAGE_SIZE): startPath = i endPath = i + PAGE_SIZE if endPath > MAX_PAGE: endPath = MAX_PAGE print startPath, ",", endPath t = MyThread("Thread " + str(count), startPath, endPath) count=count+1 t.start() pass