python3 多线程爬虫模板

原文:https://www.jianshu.com/p/06ae2373f560

  1 import threading  # 多线程模块
  2 import queue  # 队列模块
  3 import requests
  4 from lxml import etree
  5 import time
  6 import random
  7 import json
  8 
  9 concurrent = 3  # 采集线程数
 10 conparse = 3  # 解析线程                 
 11 
 12 
 13 class Parse(threading.Thread):  # 解析线程类
 14     # 初始化属性
 15     def __init__(self, number, data_list, req_thread, f):
 16         super(Parse, self).__init__()
 17         self.number = number  # 线程编号
 18         self.data_list = data_list  # 数据队列
 19         self.req_thread = req_thread  # 请求队列,为了判断采集线程存活状态
 20         self.f = f  # 获取文件对象
 21         self.is_parse = True  # 判断是否从数据队列里提取数据
 22 
 23 
 24 def run(self):
 25     print('启动%d号解析线程' % self.number)
 26     # 无限循环,
 27     while True:
 28         # 如何判断解析线程的结束条件
 29         for t in self.req_thread:  # 循环所有采集线程
 30             if t.is_alive():  # 判断线程是否存活
 31                 break
 32         else:  # 如果循环完毕,没有执行break语句,则进入else
 33             if self.data_list.qsize() == 0:  # 判断数据队列是否为空
 34                 self.is_parse = False  # 设置解析为False
 35         # 判断是否继续解析
 36         if self.is_parse:  # 解析
 37             try:
 38                 data = self.data_list.get(timeout=3)  # 从数据队列里提取一个数据
 39             except Exception as e:  # 超时以后进入异常
 40                 data = None
 41             # 如果成功拿到数据,则调用解析方法
 42             if data is not None:
 43                 self.parse(data)  # 调用解析方法
 44         else:
 45             break  # 结束while 无限循环
 46     print('退出%d号解析线程' % self.number)
 47 
 48 
 49 # 页面解析函数
 50 def parse(self, data):
 51     html = etree.HTML(data)
 52     # 获取所有段子div
 53     duanzi_div = html.xpath('//div[@id="content-left"]/div')
 54     for duanzi in duanzi_div:
 55         # 获取昵称
 56         nick = duanzi.xpath('./div//h2/text()')[0]
 57         nick = nick.replace('
', '')
 58         # 获取年龄
 59         age = duanzi.xpath('.//div[@class="author clearfix"]/div/text()')
 60         if len(age) > 0:
 61             age = age[0]
 62         else:
 63             age = 0
 64         # 获取性别
 65         gender = duanzi.xpath('.//div[@class="author clearfix"]/div/@class')
 66     if len(gender) > 0:
 67         if 'women' in gender[0]:
 68             gender = ''
 69         else:
 70             gender = ''
 71     else:
 72         gender = ''
 73         # 获取段子内容
 74     content = duanzi.xpath('.//div[@class="content"]/span[1]/text()')[0].strip()
 75     # 获取好笑数
 76     good_num = duanzi.xpath('./div//span[@class="stats-vote"]/i/text()')[0]
 77     # 获取评论
 78     common_num = duanzi.xpath('./div//span[@class="stats-comments"]//i/text()')[0]
 79     item = {
 80         'nick': nick,
 81         'age': age,
 82         'gender': gender,
 83         'content': content,
 84         'good_num': good_num,
 85         'common_num': common_num,
 86     }
 87     self.f.write(json.dumps(item, ensure_ascii=False) + '
')
 88 
 89 
 90 class Crawl(threading.Thread):  # 采集线程类
 91     # 初始化
 92     def __init__(self, number, req_list, data_list):
 93         # 调用Thread 父类方法
 94         super(Crawl, self).__init__()
 95         # 初始化子类属性
 96         self.number = number
 97         self.req_list = req_list
 98         self.data_list = data_list
 99         self.headers = {
100             'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.89 Safari/537.36'
101         }
102         # 线程启动的时候调用
103 
104     def run(self):
105         # 输出启动线程信息
106         print('启动采集线程%d号' % self.number)
107         # 如果请求队列不为空,则无限循环,从请求队列里拿请求url
108         while self.req_list.qsize() > 0:
109             # 从请求队列里提取url
110             url = self.req_list.get()
111             print('%d号线程采集:%s' % (self.number, url))
112             # 防止请求频率过快,随机设置阻塞时间
113             time.sleep(random.randint(1, 3))
114             # 发起http请求,获取响应内容,追加到数据队列里,等待解析
115             response = requests.get(url, headers=self.headers)
116             if response.status_code == 200:
117                 self.data_list.put(response.text)  # 向数据队列里追加  
118                 
119                 
120 def main():
121     # 生成请求队列
122     req_list = queue.Queue()
123     # 生成数据队列 ,请求以后,响应内容放到数据队列里
124     data_list = queue.Queue()
125     # 创建文件对象
126     f = open('duanzi.json', 'w', encoding='utf-8')
127     # 循环生成多个请求url
128     for i in range(1, 13 + 1):
129         base_url = 'https://www.qiushibaike.com/8hr/page/%d/' % i
130         # 加入请求队列
131         req_list.put(base_url)
132     # 生成N个采集线程
133     req_thread = []
134     for i in range(concurrent):
135         t = Crawl(i + 1, req_list, data_list)  # 创造线程
136         t.start()
137         req_thread.append(t)
138     # 生成N个解析线程
139     parse_thread = []
140     for i in range(conparse):
141         t = Parse(i + 1, data_list, req_thread, f)  # 创造解析线程
142         t.start()
143         parse_thread.append(t)
144     for t in req_thread:
145         t.join()
146     for t in parse_thread:
147         t.join()
148     # 关闭文件对象
149     f.close()
150 
151 if __name__ == '__main__':
152     main()
原文地址:https://www.cnblogs.com/DirWang/p/11878474.html