(三十二) 初遇python之json模块

import json

#定义一个json字符串
people_str = '''
{
  "people":[
    {
      "name":"yale",
      "age" : 25,
      "email" :"yale@email.com"
    },
    {
      "name":"McBag",
      "age" : 30,
      "email" :null
    }
  ]
}
'''
#使用json.loads()加载字符串
data = json.loads(people_str)
print(data)
#返回的是一个python字典
#{'people': [{'name': 'yale', 'age': 25, 'email': 'yale@email.com'}
#, {'name': 'McBag', 'age': 30, 'email': None}]}
print(type(data['people']))#返回<class 'list'>
#我们循环读取数据
for people in data['people']:
  print(people)
  #print(people['name'])
#{'name': 'yale', 'age': 25, 'email': 'yale@email.com'}
#{'name': 'McBag', 'age': 30, 'email': None}
#删除email信息
for people in data['people']:
  del people['email']
#使用json.dumps()
#将Python对象编码成JSON字符串
#indent缩进显示
#sort_keys按照key排序
new_string = json.dumps(data,indent=1,sort_keys=True)
print(new_string)
#打印结果:
'''
{
 "people": [
  {
   "name": "yale",
   "age": 25
  },
  {
   "name": "McBag",
   "age": 30
  }
 ]
}
'''
#加载json文件
with open('people.json','r') as f:
  data = json.load(f)
#打印数据
for person in data['people']:
  print(person['name'],person['age'],person['email']) 
#写入json文件
for person in data['people']:
  del person['email']
with open('new_data.json','w') as wf:
  new_json = json.dumps(data,indent=2)
  wf.write(new_json)
#读取新浪新闻的json
import re
from urllib.request import urlopen
#请求一个新浪新闻地址
with urlopen('''http://top.news.sina.com.cn/ws/GetTopDataList.php?top_type=day&top_cat=qbpdpl&top_time=20190531&top_show_num=100&top_order=DESC&js_var=comment_all_data''') as response:
   source = response.read()
   source = source.decode()
#正则匹配出json字符串部分   
try:
  pattern = re.compile(r'\{\"conf\".*\}\]\}')
  matches = pattern.findall(source)
  data = json.loads(matches[0])
  for item in data['data']:
    print(item['id'],item['title'])
except Exception as e:
  print('出错了',e)
#部分运行效果:
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#5229 《破冰行动》导演为逻辑Bug道歉 回应感情戏多余

{'people': [{'name': 'yale', 'age': 25, 'email': 'yale@email.com'}
, {'name': 'McBag', 'age': 30, 'email': None}]}
<class 'list'>
{'name': 'yale', 'age': 25, 'email': 'yale@email.com'}
{'name': 'McBag', 'age': 30, 'email': None}
{
 "people": [
  {
   "age": 25,
   "name": "yale"
  },
  {
   "age": 30,
   "name": "McBag"
  }
 ]
}
yale 25 yale@email.com
McBag 30 None
TestUser 30 testuser@163.com
5208 《破冰行动》导演为逻辑Bug道歉 回应感情戏多余
5215 库里34+5双卡55分 猛龙击退勇士总决赛1-0领先
......