python：Json模块dumps、loads、dump、load介绍

转载请注明出处：https://www.cnblogs.com/shapeL/p/9037670.html

由上篇文章（python3+requests：get/post请求）涉及到的json.dumps()扩展

1.json.dumps()用于将dict类型的数据转成str

备注：文件路径前面加上 r 是为了避免转义

 import json

 dict = {'a': 'wo', 'b': 'zai', 'c': 'zhe', 'd': 'li'}
 string = json.dumps(dict)
 print(dict)
 print(string)
 print(type(dict))
 print(type(string))

 with open(r'C:\Users\zy\Documents\GitHub\python3\searchTest\json.json','w')as f:
     f.write(string)

 {'a': 'wo', 'b': 'zai', 'c': 'zhe', 'd': 'li'}
 {"a": "wo", "b": "zai", "c": "zhe", "d": "li"}
 <class 'dict'>
 <class 'str'>

如果没有进行转换，则会报错：TypeError: write() argument must be str, not dict

 import json

 dict = {'a': 'wo', 'b': 'zai', 'c': 'zhe', 'd': 'li'}
 with open(r'C:\Users\zy\Documents\GitHub\python3\searchTest\json.json','w')as f:
     f.write(dict)

 {'a': 'wo', 'b': 'zai', 'c': 'zhe', 'd': 'li'}
 Traceback (most recent call last):
 <class 'dict'>
   File "C:/Users/zy/Documents/GitHub/python3/searchTest/json_test.py", line 11, in <module>
     f.write(dict)
 TypeError: write() argument must be str, not dict

json.dumps()参数解释：常用参数解释

indent：应该是一个非负的整型，如果是0，或者为空，则一行显示数据；否则会换行且按照indent的数量显示前面的空白

sort_keys：将数据根据keys的值进行排序

 response = requests.post(url=url,headers=headers).json()
 print(json.dumps(response,sort_keys=True,indent=))

举例结果：

 {
     "code": "",
     "message": "",
     "redirect": "",
     "value": {
         "name": "so",
         "title": "",
         "value": ""
     }
 }

2.json.loads():用于将str类型的数据转成dict

 dict = {'a': 'wo', 'b': 'zai', 'c': 'zhe', 'd': 'li'}
 dumps = json.dumps(dict)
 loads = json.loads(dumps)

 print(dict)
 print(dumps)
 print(loads)

 print(type(dict))
 print(type(dumps))
 print(type(loads))

 {'a': 'wo', 'b': 'zai', 'c': 'zhe', 'd': 'li'}
 {"a": "wo", "b": "zai", "c": "zhe", "d": "li"}
 {'a': 'wo', 'b': 'zai', 'c': 'zhe', 'd': 'li'}
 <class 'dict'>
 <class 'str'>
 <class 'dict'>

3.json.dump()用于将dict类型的数据转成str，并写入到json文件中

 dict = {'a': 'wo', 'b': 'zai', 'c': 'zhe', 'd': 'li'}
 json.dump(dict,open(r'C:\Users\zy\Documents\GitHub\python3\searchTest\json.json','w'))

4.json.load()用于从json文件中读取数据

 filename = (r'C:\Users\zy\Documents\GitHub\python3\searchTest\json.json')
 jsObj = json.load(open(filename))
 print(jsObj)
 print(type(jsObj))

 {'a': 'wo', 'b': 'zai', 'c': 'zhe', 'd': 'li'}
 <class 'dict'>