用队列方式实现多线程爬虫
声明：无意滋生事端，仅学习分享，如有侵权，将立即删除。
说明：糗事百科段子的爬取，采用了队列和多线程的方式，其中关键点是Queue.task_done()、Queue.join()，保证了线程的有序进行。
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
新版
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
import requests from lxml import etree from queue import Queue from threading import Thread from multiprocessing.dummy import Pool import json import time class Qsbk(object): """ 主要类，用来实现主要模型 """ def __init__(self): self.headers = { "User-Agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36", } self.start_url = "https://www.qiushibaike.com/text" # 实例化三个队列，用来存放内容 # 这时线程是安全的 self.url_queue = Queue() self.html_queue = Queue() self.content_queue = Queue() def get_total_url(self): """获取所有页面的url,并返回url_list""" # 构造url列表，拼接第一个url和second个url url_list = list() url_list.append(self.start_url) second_url = "https://www.qiushibaike.com/text/page/{}/" for i in range(2, 14): url = second_url.format(str(i)) url_list.append(url) # 将url添加到队列中 for url in url_list: self.url_queue.put(url) def get_response_html(self): """获取响应的html""" while self.url_queue.not_empty: # 判断非空，为空的时候结束循环 # 从队列中取出一个url url = self.url_queue.get() print("parse url:",url) # 获取response response = requests.get(url, headers=self.headers,timeout=1) # 将response变为字符串 response_str = response.content.decode() # 将response_str变为etree.HTML对象 html = etree.HTML(response_str) # 将lxml实例化的html添加到html_queue self.html_queue.put(html) """ 表明先前排队的任务已经完成， 由队列使用者在线程中使用。 对于用于获取任务的每个get()，随后对task_done()的调用告诉队列该处理任务完成了 如果join()当前处于阻塞状态，则将在处理完所有项目后恢复。 """ # task_done的时候，队列计数减一 self.url_queue.task_done() def get_content(self): """ 返回content_list 获取内容： 用户头像连接、用户姓名、段子内容、段子详情页、点赞次数和评论次数 user_image_href user_name content content_detail_href stats_vote stats_comments user_gender user_age """ while self.html_queue.not_empty: # 创建一个content_list存放当前页下的所有div中包涵的段子信息 content_list = list() # 从html_queue队列中获取单页的lxml化的html html = self.html_queue.get() # 获取单个页面的所有包含段子的div列表 div_all = html.xpath("//div[@class='col1 old-style-col1']/div") # 创建一个列表，存当单页下所有的单个段子元素组成的字典 # 获取单个段子div下的内容 for div in div_all: # 创建一个字典，存放单个div下的内容 content_dict = dict() user_image_href = div.xpath(".//div[@class='author clearfix']//img/@src") user_image_href = "https:"+user_image_href[0].split("?")[0].strip() if user_image_href else None user_name = div.xpath(".//div[@class='author clearfix']//img/@alt") user_name = user_name[0].strip() if user_name else None content = div.xpath(".//a[@class='contentHerf']//span/text()") content = content[0].strip() if content else None content_detail_href = div.xpath(".//a[@class='contentHerf']/@href") content_detail_href ="https://www.qiushibaike.com"+content_detail_href[0].strip() if content_detail_href else None stats_vote = div.xpath(".//div[@class='stats']/span[@class='stats-vote']//i/text()") stats_vote = stats_vote[0] if stats_vote else None stats_comment = div.xpath(".//div[@class='stats']/span[@class='stats-comments']//i/text()") stats_comment = stats_comment[0] if stats_comment else None user_gender = div.xpath(".//div[@class='author clearfix']/div/@class") user_gender = user_gender[0].split(" ")[-1].replace("Icon","").strip() if user_gender else None user_age = div.xpath(".//div[@class='author clearfix']/div/text()") user_age = user_age[0] if user_age else None content_dict["user_image_href"] = user_image_href content_dict["user_name"] = user_name content_dict["user_gender"] = user_gender content_dict["user_age"] = user_age content_dict["content"] = content content_dict["content_detail_href"] = content_detail_href content_dict["stats_vote"] = stats_vote content_dict["stats_comment"] = stats_comment content_list.append(content_dict) # 将获得到的单页content_list放入content_queue中 self.content_queue.put(content_list) # task_done的时候，队列计数减一 self.html_queue.task_done() def save_content_to_file(self): """ 保存文件为json """ while self.content_queue.not_empty: content_list = self.content_queue.get() with open("qiushibaike_duanzi.json",'a',encoding='utf8') as f: f.write(json.dumps(content_list,ensure_ascii=False,indent=2)) print("写入完成") # task_done的时候，队列计数减一 self.content_queue.task_done() def run(self): """ 实现主要逻辑 """ start_ = time.time() # 创建线程列表 thread_list = list() # 创建获取total_url的线程 url_thread = Thread(target=self.get_total_url) # 添加url_thread到thread_list中 thread_list.append(url_thread) # 创建获取response_html的线程 html_thread = Thread(target=self.get_response_html) # 添加html_thread到thread_list中 thread_list.append(html_thread) # 创建获取content的线程 content_thread = Thread(target=self.get_content) # 添加content_thread到thread_list中 thread_list.append(content_thread) # 创建保存content的线程 savefile_thread = Thread(target=self.save_content_to_file) # 添加到thread_list thread_list.append(savefile_thread) # 方式一 # for t in thread_list: # # 将每个进程设置为守护进程，效果是主进程退出后，不等子进程执行完也退出 # # 进程守护文章： # t.setDaemon(True) # t.start() # # 当主线程等待，所有的队列为空的时候才能退出 # self.url_queue.join() # self.html_queue.join() # self.content_queue.join() # 方式二 def process_thread(t): # 设置守护进程：https://www.cnblogs.com/nuochengze/p/12882349.html t.daemon=True t.start() pool = Pool(10) pool.map(process_thread,thread_list) # 当主线程等待，所有的队列为空的时候才能退出 self.url_queue.join() self.html_queue.join() self.content_queue.join() ends_ = time.time() print("运行时间：",ends_-start_) if __name__=='__main__': obj = Qsbk() obj.run()
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
旧版
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
import requests from lxml import etree import json from queue import Queue import threading class Qsbk(object): def __init__(self): self.headers = { "User-Agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36", "Referer": "https://www.qiushibaike.com/" } # 实例化三个队列，用来存放内容 self.url_queue = Queue() self.html_queue = Queue() self.content_queue = Queue() def get_total_url(self): """ 获取了所有的页面url，并且返回url_list return:url_list 现在放入url_queue队列中保存 """ url_temp = "https://www.qiushibaike.com/text/page/{}/" url_list = list() for i in range(1,13): # url_list.append(url_temp.format(i)) # 将生成的url放入url_queue队列 self.url_queue.put(url_temp.format(i)) def parse_url(self): """ 发送请求，获取响应，同时etree处理html """ while self.url_queue.not_empty: # 判断非空，为空时结束循环 # 从队列中取出一个url url = self.url_queue.get() print("parsing url:",url) # 发送请求 response = requests.get(url,headers=self.headers,timeout=10) # 获取html字符串 html = response.content.decode() # 获取element类型的html html = etree.HTML(html) # 将生成的element对象放入html_queue队列 self.html_queue.put(html) # Queue.task_done() 在完成一项工作之后，Queue.task_done()函数向任务已经完成的队列发送一个信号 self.url_queue.task_done() def get_content(self): """ 解析网页内容，获取想要的信息 """ while self.html_queue.not_empty: items = list() html = self.html_queue.get() total_div = html.xpath("//div[@class='col1 old-style-col1']/div") for i in total_div: author_img = i.xpath(".//a[@rel='nofollow']/img/@src") author_img = "https"+author_img[0] if len(author_img)>0 else None author_name = i.xpath(".//a[@rel='nofollow']/img/@alt") author_name = author_name[0] if len(author_name)>0 else None author_href = i.xpath("./a/@href") author_href = "https://www.qiushibaike.com/"+author_href[0] if len(author_href)>0 else None author_gender = i.xpath("./div[1]/div/@class") author_gender = author_gender[0].split(" ")[-1].replace("Icon","").strip() if len(author_gender)>0 else None author_age = i.xpath("./div[1]/div/text()") author_age = author_age[0] if len(author_age)>0 else None content = i.xpath("./a/div/span/text()") content = content[0].strip() if len(content)>0 else None content_vote = i.xpath("./div[@class='stats']/span[@class='stats-vote']/i/text()") content_vote = content_vote[0] if len(content_vote)>0 else None content_comment_numbers = i.xpath("./div[@class='stats']/span[@class='stats-comments']/a/i/text()") content_comment_numbers = content_comment_numbers[0] if len(content_comment_numbers)>0 else None item = { "author_name":author_name, "author_age" :author_age, "author_gender":author_gender, "author_img":author_img, "author_href":author_href, "content":content, "content_vote":content_vote, "content_comment_numbers":content_comment_numbers, } items.append(item) self.content_queue.put(items) # task_done的时候，队列计数减一 self.html_queue.task_done() def save_items(self): """ 保存items """ while self.content_queue.not_empty: items = self.content_queue.get() with open("quishibaike.txt",'a',encoding='utf-8') as f: for i in items: json.dump(i,f,ensure_ascii=False,indent=2) self.content_queue.task_done() def run(self): # 获取url list thread_list = list() thread_url = threading.Thread(target=self.get_total_url) thread_list.append(thread_url) # 发送网络请求 for i in range(10): thread_parse = threading.Thread(target=self.parse_url) thread_list.append(thread_parse) # 提取数据 thread_get_content = threading.Thread(target=self.get_content) thread_list.append(thread_get_content) # 保存 thread_save = threading.Thread(target=self.save_items) thread_list.append(thread_save) for t in thread_list: # 为每个进程设置为后台进程，效果是主进程退出子进程也会退出 t.setDaemon(True) t.start() # 让主线程等待，所有的队列为空的时候才能退出 self.url_queue.join() self.html_queue.join() self.content_queue.join() if __name__=="__main__": obj = Qsbk() obj.run()
