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学习日志2

        这节内容学习了JSON基础概述，JSON模块，XML文件与JSON文件互转，解析JSON文件。现在进行复盘及应用。

1.新建一个python对象（字典）

python_str={
	"season":
	[
		{"spring":{"fruit":"pineapple"}},
		{"summer":{"fruit":["watermelon","peach"]}},
		{"fall":{"fruit": "apple"}},
        {"winter":{"fruit": "orange"}}
    ]
}

2.将python字典转化为json字符串（json.dumps()方法）

​
json_str=json.dumps(python_str)
 
#输出
{"season": [{"spring": {"fruit": "pineapple"}}, {"summer": {"fruit": ["watermelon", "peach"]}}, {"fall": {"fruit": "apple"}}, {"winter": {"fruit": "orange"}}]}
 
​

        2.1格式化输出

json_str=json.dumps(python_str,sort_keys=True,indent=3)
print(json_str)
 
#输出
{
   "season": [
      {
         "spring": {
            "fruit": "pineapple"
         }
      },
      {
         "summer": {
            "fruit": [
               "watermelon",
               "peach"
            ]
         }
      },
      {
         "fall": {
            "fruit": "apple"
         }
      },
      {
         "winter": {
            "fruit": "orange"
         }
      }
   ]
}
 
进程已结束,退出代码0

 3.将python字典转化为json字符串并存入json文件中（json.dump()方法）

        3.1新建一个空的json文件

        3.2转换并写入json文件中

json.dump(python_str,open("./json.file.json","w"),sort_keys=True,indent=3)

         存储结果：

 4.将json格式的字符串转换为python类型（json.loads()方法）

​
python_str=json.loads(json_str)
 
​
#输出
{'season': [{'spring': {'fruit': 'pineapple'}}, {'summer': {'fruit': ['watermelon', 'peach']}}, {'fall': {'fruit': 'apple'}}, {'winter': {'fruit': 'orange'}}]}
 

5.从json格式文件中读取数据转化为python类型（json.load()方法）

python_str=json.load(open("./json.file.json","r"))
print(python_str)
#输出
{'season': [{'spring': {'fruit': 'pineapple'}}, {'summer': {'fruit': ['watermelon', 'peach']}}, {'fall': {'fruit': 'apple'}}, {'winter': {'fruit': 'orange'}}]}

 6.XML文件与json文件转化

安装模块——

pip install xmltodict

        6.1 xml文件转为json文件

新建一个1.xml文件：

 转换代码：

import json
import xmltodict
def xml_to_json(xml_str):
	xml_parse=xmltodict.parse(xml_str)
	json_str=json.dumps(xml_parse,indent=2)
	return json_str
xml_path='./1.xml'
f=open(xml_path,"r")
xml_file=f.read()
with open('./1.jsonfile.json',"w") as newf:
	newf.write(xml_to_json(xml_file))

输出：

         6.2 json文件转化为xml文件

转换代码：

import json
import xmltodict
def json_to_xml(python_dir):
	xml_str=xmltodict.unparse(python_dir)
	return xml_str
 
json_path="./1.jsonfile.json"
f=open(json_path,"r")
json_file=f.read()
python_dir=json.loads(json_file)
with open("./2.xml","w") as fp:
	fp.write(json_to_xml(python_dir))
 
#原内容
{
  "action": {
    "@year": "3/08/2022",
    "season": [
      "summer",
      "winter"
    ],
    "incident": "miss"
  }
}
#写入xml文件内容
"1.0" encoding="utf-8"?>
"3/08/2022">summerwintermiss

7.json字符串解析

import json
python_str={
	"season":
		[
		{"spring":[{"fruit":"pineapple"}]},
		{"summer":[{"fruit":["watermelon","peach"]}]},
		{"fall":[{"fruit": "apple"}]},
        {"winter":[{"fruit": "orange"}]}
		]
}
#定位数据节点
#打印字典所有key
print(python_str.keys())
#打印字典所有value
print(python_str.values())
print(python_str["season"][0])
print(python_str["season"][1])
 
#输出
dict_keys(['season'])
dict_values([[{'spring': [{'fruit': 'pineapple'}]}, {'summer': [{'fruit': ['watermelon', 'peach']}]}, {'fall': [{'fruit': 'apple'}]}, {'winter': [{'fruit': 'orange'}]}]])
{'spring': [{'fruit': 'pineapple'}]}
{'summer': [{'fruit': ['watermelon', 'peach']}]}

 8.解析json文件

import json
 
# 1、JSON文件转换为Python对象
python_obj = json.load(open('test.json', 'r'))
print(python_obj)
print(type(python_obj))
 
print("-" * 20)
# 2、解析json文件
 
# 输出cours节点e下的数据
print(python_obj['student']['course']['name'])  # 输出name
print(python_obj['student']['course']['score'])  # 输出score
 
# 输出info节点下的数据
print(python_obj['student']['info']['sex'])  # 输出sex
print(python_obj['student']['info']['name'])  # 输出name
 
# 输出stid节点下的数据
print(python_obj['student']['stid'])  # 输出stid