初步运用多进程，利用正则表达式，爬取猫眼电影top100排行榜，储存到本地

import re
import requests
from requests.exceptions import RequestException
import json
from fake_useragent import UserAgent
from multiprocessing import Pool

def get_one_page(url):
try:
"""
response = requests.get(url)   # 以前的代码没有伪装也行，今天试了下不行了，提示被禁止
"""
"""
# 用自己复制过来的UA
headers = {'User-Agent':'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36'}
"""
# 新发现的用fake_UA包
headers = {'User-Agent': UserAgent().random}
response = requests.get(url,headers = headers)
if response.status_code == 200:
return response.text
return None
except RequestException:
return None

def parse_one_page(html):
# re.S：匹配换行符
# 匹配：排名，名字，演员，上映时间，评分
pattern = re.compile('<dd>.*?board-index.*?>(\d+)</i>.*?data-src="(.*?)".*?name"><a'
+'.*?>(.*?)</a>.*?star">(.*?)</p>.*?releasetime">(.*?)</p>'
+'.*?integer">(.*?)</i>.*?fraction">(.*?)</i>.*?</dd>', re.S)
items = re.findall(pattern, html)  # findall以列表形式返回
#print(items)
for item in items:
# 以迭代器的形式返回字典形式的内容
yield {
'index': item[0],
'image': item[1],
'title': item[2],
'actor': item[3].strip()[3:],  # strip()去掉字符串首尾空白符
'time': item[4].strip()[5:],
'score': item[5]+item[6]
}

def write_to_file(content):
# 编码转换
with open('result.txt', 'a', encoding='utf-8') as f:
# dumps 将dict转换成str格式
# loads 将str转换成dict格式
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)
#print(html)
#parse_one_page(html)
for item in parse_one_page(html):
print(item)
write_to_file(item)

if __name__ == '__main__':
#main()
#     for i in range(10):  # 爬取多个页面，用for语句来生成翻页内容
#         main(i*10)
pool = Pool()  # 开启进程池
pool.map(main,[i*10 for i in range(10)])
pool.close()
pool.join()