Requests加正则表达式抓取猫电影信息

#Author:donghuiya
#这是抓取猫眼电影前100页，分四步：
#1.得到网页源代码
#2.用正则表达式获得所需要的内容
#3.写入文件中
#4.用多进程更快
import requests
from requests.exceptions import RequestException
import re
import json
from multiprocessing import Pool
def get_one_page(url):
    try:
        response=requests.get(url)
        if response.status_code==200:
            return response.text
        return None
    except RequestException:
        return None
def parse_one_page(html):
    pattern=re.compile('<dd>.*?board-index.*?>(.*?)</i>.*?name"><a.*?>(.*?)</a>.*?star">(.*?)</p>.*?releasetime">(.*?)</p>.*?integer">(.*?)'
                       +'</i>.*?fraction">(.*?)</i>.*?</dd>',re.S)
    items=re.findall(pattern,html)
    for item in items:
        yield{
            'index':item[0],
            'title':item[1],
            'actor':item[2].strip()[3:],
            'time':item[3].strip()[5:],
            'score':item[4]+item[5]
        }
def write_to_file(content):
    with open('result1.txt','a',encoding="utf-8") as f:
        f.write(json.dumps(content,ensure_ascii=False)+'\n')
        f.close()
def main(offset):
    url='http://maoyan.com/board/4?offset='+str(offset)
    html=get_one_page(url)
    for item in parse_one_page(html):
        print(item)
        write_to_file(item)
if __name__=='__main__':
    pool=Pool()
    pool.map(main,[i*10 for i in range(10)])