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這篇文章主要講解了Python使用隊(duì)列方式實(shí)現(xiàn)多線程爬蟲的方法,內(nèi)容清晰明了,對此有興趣的小伙伴可以學(xué)習(xí)一下,相信大家閱讀完之后會有幫助。
說明:糗事百科段子的爬取,采用了隊(duì)列和多線程的方式,其中關(guān)鍵點(diǎn)是Queue.task_done()、Queue.join(),保證了線程的有序進(jìn)行。
代碼如下
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/" } # 實(shí)例化三個(gè)隊(duì)列,用來存放內(nèi)容 self.url_queue = Queue() self.html_queue = Queue() self.content_queue = Queue() def get_total_url(self): """ 獲取了所有的頁面url,并且返回url_list return:url_list 現(xiàn)在放入url_queue隊(duì)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)) # 將生成的url放入url_queue隊(duì)列 self.url_queue.put(url_temp.format(i)) def parse_url(self): """ 發(fā)送請求,獲取響應(yīng),同時(shí)etree處理html """ while self.url_queue.not_empty: # 判斷非空,為空時(shí)結(jié)束循環(huán) # 從隊(duì)列中取出一個(gè)url url = self.url_queue.get() print("parsing url:",url) # 發(fā)送請求 response = requests.get(url,headers=self.headers,timeout=10) # 獲取html字符串 html = response.content.decode() # 獲取element類型的html html = etree.HTML(html) # 將生成的element對象放入html_queue隊(duì)列 self.html_queue.put(html) # Queue.task_done() 在完成一項(xiàng)工作之后,Queue.task_done()函數(shù)向任務(wù)已經(jīng)完成的隊(duì)列發(fā)送一個(gè)信號 self.url_queue.task_done() def get_content(self): """ 解析網(wǎng)頁內(nèi)容,獲取想要的信息 """ 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的時(shí)候,隊(duì)列計(jì)數(shù)減一 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): # 獲取url list thread_list = list() thread_url = threading.Thread(target=self.get_total_url) thread_list.append(thread_url) # 發(fā)送網(wǎng)絡(luò)請求 for i in range(10): thread_parse = threading.Thread(target=self.parse_url) thread_list.append(thread_parse) # 提取數(shù)據(jù) 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: # 為每個(gè)進(jìn)程設(shè)置為后臺進(jìn)程,效果是主進(jìn)程退出子進(jìn)程也會退出 t.setDaemon(True) t.start() # 讓主線程等待,所有的隊(duì)列為空的時(shí)候才能退出 self.url_queue.join() self.html_queue.join() self.content_queue.join() if __name__=="__main__": obj = Qsbk() obj.run()
看完上述內(nèi)容,是不是對Python使用隊(duì)列方式實(shí)現(xiàn)多線程爬蟲的方法有進(jìn)一步的了解,如果還想學(xué)習(xí)更多內(nèi)容,歡迎關(guān)注億速云行業(yè)資訊頻道。
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