import re

 ret = re.search('<(?P<tag_name>\w+)>\w+</(?P=tag_name)>','<h1>hello</h1>')

 #还可以在分组中利用?P<name>的形式给分组起名字

 #获取的匹配结果可以直接用group('名字')拿到对应的值

 print(ret.group())

 print(ret.group('tag_name'))

 # -------------------------

 ret = re.search(r'<(\w+)>\w+</\1>','<h1>hello</h1>')

 #如果不给分组起名字，也可以用\序号来找到对应的组，表说要找的内容和前面的组的内容一致

 #获取的匹配结果可以直接用group(序号)拿到对应的值

 print(ret.group())

 print(ret.group(1))

 import re

 ret = re.findall(r'\d+',"1-2*(60+(-40.35/5)-(-4*3))")

 print(ret)

 import re

 ret = re.findall(r'-?\d+\.\d*|(-?\d+)',"1-2*(60+(-40.35/5)-(-4*3))")

 print(ret)

 ret.remove('')

 print(ret)

 # 3.数字匹配

 # 1.匹配一段文本中的每行的时间字符串，比如’1990-07-12‘

 # 1.分别取出一年的十二个月：

 while True:

     cmd = input('请输入月份：>>')

     if re.match(r'^(0?[1-9]|1[0-2])$',cmd):

         print('格式正确')

     else:

         print('格式错误')

 # 2.

 ret =re.match(r'^(0?[1-9]|1[0-2])$','')

 print(ret.group())

 # 一个月的31天

 ret = re.match(r'^((0?[1-9])|((1|2)[0-9])|30|31)$','')#从头匹配

 print(ret.group())

 # 匹配QQ号

 while True:

     cmd = input('请输入你扣扣号：>>')

     if re.match(r'^[1-9][0-9]{4,10}$',cmd):

         print('输入正确')

     else:

         print('输入错误')

 # 浮点数

 ret = re.match(r'-?\d+\.?\d*','21.5')

 print(ret.group())

 import requests

 import re

 import json

 def getPage(url):

     response=requests.get(url)

     return response.text

 def parsePage(s):

     com=re.compile('<div class="item">.*?<div class="pic">.*?<em .*?>(?P<id>\d+).*?<span class="title">(?P<title>.*?)</span>'

                    '.*?<span class="rating_num" .*?>(?P<rating_num>.*?)</span>.*?<span>(?P<comment_num>.*?)评价</span>',re.S)

     ret=com.finditer(s)

     for i in ret:

         yield {

             "id":i.group("id"),

             "title":i.group("title"),

             "rating_num":i.group("rating_num"),

             "comment_num":i.group("comment_num"),

         }

 def main(num):

     url='https://movie.douban.com/top250?start=%s&filter='%num

     response_html=getPage(url)

     ret=parsePage(response_html)

     print(ret)

     f=open("move_info7","a",encoding="utf8")

     for obj in ret:

         print(obj)

         data=json.dumps(obj,ensure_ascii=False)

         f.write(data+"\n")

 if __name__ == '__main__':

     count=0

     for i in range(10):

         main(count)

         count+=25