import json
import re
import requests
from bs4 import BeautifulSoup
from requests import RequestException
from multiprocessing import Pool
def get_one_page(url):
    headers = {‘User-Agent‘:‘baiduspider+‘}
    try:
        response = requests.get(url,headers=headers,timeout = 5)
        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.*?>(\d+)</i>.*?src="http://www.mamicode.com/(.*?)".*?name"><a.*?(.*?)</a>.*?star">(.*?)</p>.*?releasetime">(.*?)</p>.*?integer">(.*?)<i>.*?fraction">(.*?)</i>.*?</dd>‘,re.S)
    #items = re.findall(pattern,html)
    for item in BeautifulSoup(html,‘lxml‘).find_all(‘dd‘):
        rank = item.select(‘i‘)[0].text
        name = item.select(‘p > a‘)[0].text
        star = item.select(‘.star‘)[0].text.strip()
        releasetime = item.select(‘.releasetime‘)[0].text
        integer = item.select(‘.integer‘)[0].text
        fraction = item.select(‘.fraction‘)[0].text
        grade = integer+fraction
        yield {
            ‘rank‘:rank,
            ‘name‘:name,
            ‘star‘:star,
            ‘releasetime‘:releasetime,
            ‘grade‘:grade
        }
        #print(rank,name,star,releasetime,‘评分为：‘,integer+fraction)
        #return rank,name,star,releasetime,‘评分为：‘,integer+fraction
def write_to_file(content):
    with open(‘result.txt‘,‘a‘,encoding=‘utf-8‘) as f:
        f.write(json.dumps(content,ensure_ascii=False) + ‘\n‘)#将字典转化为字符串
        f.close()
def main(offset):
    url = ‘http://maoyan.com/board/4?offset=‘ + str(offset)
    html = get_one_page(url)
    parse_one_page(html)
    for item in parse_one_page(html):
       print(item)
       write_to_file(item)

if __name__=="__main__":
    for i in range(10):
        main(i*10)
    #pool = Pool()
    #pool.map(main,[i*10 for i in range(10)])

20170513爬取猫眼电影Top100