爬虫：多进程爬虫

　　本文测试代码要利用到上一篇文章爬取到的数据，上一章链接：爬虫：获取动态加载数据（selenium）（某站） ，本文要爬取的内容是某乎提问上面的话题关键字

1. 多进程语法

1.1 语法1

import multiprocessing
import time


def func(x):
    print(x*x)


if __name__ == '__main__':
    start = time.time()
    jobs = []
    for i in range(5):
        p = multiprocessing.Process(target=func, args=(i, ))
        jobs.append(p)
        p.start()
    end = time.time()
    print(end - start)

截图如下：先打印时间不知怎么解释？求大佬指点

1.2 语法2

from multiprocessing import Pool
import time


def func(x, y):
    print(x+y)


if __name__ == '__main__':
    pool = Pool(5)
    start = time.time()
    for i in range(100):
        pool.apply_async(func=func, args=(i, 3))
    pool.close()
    pool.join()
    end = time.time()
    print(end - start)

 

2. 实践测试代码

import requests
from bs4 import BeautifulSoup
import time
from requests.exceptions import RequestException
from pymongo import MongoClient
from multiprocessing import Pool
client = MongoClient('localhost')
db = client['test_db']


def get_page_keyword(url, word):
    headers = {
        'cookie': '',
        'user-agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36'
    }  # 替换为自己的cookie

    try:
        html = requests.get(url, headers=headers, timeout=5)
        html = BeautifulSoup(html.text, "html.parser")
        key_words = html.find("div", {'class': 'QuestionPage'}).find("meta", {'itemprop': 'keywords'}).attrs['content']
        print(key_words)
        with open(r'女性话题链接.txt', 'a') as file:
            file.write(key_words + '
')
            db[u'' + word + 'keyword'].insert_one({"link": url, "key_words": key_words, "time": time.ctime()})
    except RequestException:
        print('请求失败')


if __name__ == '__main__':
    input_word = input('输入链接文件所属话题(比如:女性)：')
    f = open(r'女性2021-5-16-3-8.txt')  # 自己爬取到链接的文件位置
    lines = []
    for i in f.readlines():
        lines.append(i.strip())   # 因为上次爬取链接结尾加了行结束符 EOF
    f.close()
    # 多进程测试
    pool = Pool(2)  # 数字大会快点，但笔者电脑两核，而且数字太大网站一会就说你账号异常
    start = time.time()
    for link in lines:
        pool.apply_async(func=get_page_keyword, args=(link, input_word))
    pool.close()
    pool.join()
    end = time.time()
    print(end - start)

截图：不打算重新跑了，是以前的截图