Python 爬虫，多线程爬虫，任务队列Queue

 

 

demo.py（多线程爬虫）：

# coding=utf-8
import requests
from lxml import etree
import threading
from queue import Queue

class QiubaiSpdier:
    def __init__(self):
        self.url_temp = "https://www.qiushibaike.com/8hr/page/{}/"
        self.headers = {"User-Agent":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36"}
        self.url_queue = Queue()
        self.html_queue  = Queue()
        self.content_queue = Queue()
        
    def get_url_list(self):
        for i in range(1,14):
            self.url_queue.put(self.url_temp.format(i))

    def parse_url(self):
        while True:
            url = self.url_queue.get()  # 从任务队列中取出一个任务
            print(url)
            response = requests.get(url,headers=self.headers)
            self.html_queue.put(response.content.decode())
            self.url_queue.task_done()   # 表示该任务已经完成。 配合join使用

    def get_content_list(self): # 提取数据
        while True:
            html_str = self.html_queue.get()

            html = etree.HTML(html_str)
            div_list = html.xpath("//div[@id='content-left']/div")  # 分组
            content_list = []
            for div in div_list:
                item= {}
                item["content"] = div.xpath(".//div[@class='content']/span/text()")
                item["content"] = [i.replace("\n","") for i in item["content"]]
                item["content_img"] = div.xpath(".//div[@class='thumb']/a/img/@src")
                item["content_img"] = "https:"+item["content_img"][0] if len(item["content_img"])>0 else None
                content_list.append(item)
            self.content_queue.put(content_list)
            self.html_queue.task_done()

    def save_content_list(self): # 保存
        while True:
            content_list = self.content_queue.get()
            for i in content_list:
                # print(i)
                pass
            self.content_queue.task_done()

    def run(self): # 实现主要逻辑
        thread_list = []
        # 1.url_list
        t_url = threading.Thread(target=self.get_url_list)
        thread_list.append(t_url)
        # 2.遍历，发送请求，获取响应
        for i in range(20):
            t_parse = threading.Thread(target=self.parse_url)
            thread_list.append(t_parse)
        # 3.提取数据
        for i in range(2):
            t_html = threading.Thread(target=self.get_content_list)
            thread_list.append(t_html)
        # 4.保存
        t_save = threading.Thread(target=self.save_content_list)
        thread_list.append(t_save)
        for t in thread_list:
            t.setDaemon(True)  # 把子线程设置为守护线程，主线程结束，子线程自动结束
            t.start()

        for q in [self.url_queue,self.html_queue,self.content_queue]:
            q.join()  # 让主线程等待阻塞，等待队列的任务完成之后再结束主线程
                      # 当队列中的所有任务都完成(task_done)后，才会解阻塞。

        print("主线程结束")


if __name__ == '__main__':
    qiubai = QiubaiSpdier()
    qiubai.run()