說明：糗事百科段子的爬取，採用了佇列和多執行緒的方式，其中關鍵點是Queue.task_done()、Queue.join()，保證了執行緒的有序進行。

程式碼如下

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/"
    }
    # 例項化三個佇列，用來存放內容
    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，並且返回url_list
    return:url_list
    現在放入url_queue佇列中儲存
    """
    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佇列
      self.url_queue.put(url_temp.format(i))

  def parse_url(self):
    """
    傳送請求，獲取響應，同時etree處理html
    """
    while self.url_queue.not_empty:
      # 判斷非空，為空時結束迴圈

      # 從佇列中取出一個url
      url = self.url_queue.get()
      print("parsing url:",url)
      # 傳送請求
      response = requests.get(url,headers=self.headers,timeout=10)
      # 獲取html字串
      html = response.content.decode()
      # 獲取element型別的html
      html = etree.HTML(html)
      # 將生成的element物件放入html_queue佇列
      self.html_queue.put(html)
      # Queue.task_done() 在完成一項工作之後，Queue.task_done()函式向任務已經完成的佇列傳送一個訊號
      self.url_queue.task_done()

  def get_content(self):
    """
    解析網頁內容，獲取想要的資訊
    """
    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的時候，佇列計數減一
      self.html_queue.task_done()

  def save_items(self):
    """
    儲存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)

    # 傳送網路請求
    for i in range(10):
      thread_parse = threading.Thread(target=self.parse_url)
      thread_list.append(thread_parse)

    # 提取資料
    thread_get_content = threading.Thread(target=self.get_content)
    thread_list.append(thread_get_content)

    # 儲存
    thread_save = threading.Thread(target=self.save_items)
    thread_list.append(thread_save)


    for t in thread_list:
      # 為每個程序設定為後臺程序，效果是主程序退出子程序也會退出
      t.setDaemon(True)
      t.start()
    
    # 讓主執行緒等待，所有的佇列為空的時候才能退出
    self.url_queue.join()
    self.html_queue.join()
    self.content_queue.join()


if __name__=="__main__":
  obj = Qsbk()
  obj.run()

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支援我們。