Python之dict(或对象)与json之间的互相转化

在Python语言中，json数据与dict字典以及对象之间的转化，是必不可少的操作。

在Python中自带json库。通过 import json 导入。

在json模块有2个方法，

• loads()：将json数据转化成dict数据
• dumps()：将dict数据转化成json数据
• load()：读取json文件数据，转成dict数据
• dump()：将dict数据转化成json数据后写入json文件

下面是具体的示例：

dict字典转json数据

# -*- coding: utf-8 -*-

import json

# dict字典转json数据
def dict_to_json():
    dict = {}
    dict['name'] = 'Joe.Ye'
    dict['age'] = 20
    dict['sex'] = 'male'
    print(dict)  # 输出: {'name': 'many', 'age': 10, 'sex': 'male'}
    j = json.dumps(dict)
    print(j)  # 输出: {"name": "many", "age": 10, "sex": "male"}

# 对象转json数据
def obj_to_json():
    stu = Student(1, 'Joe.Ye', 28, 'male', '18800000000', 'test@test.com')
    print(type(stu))  # <class 'json_test.student.Student'>
    stu = stu.__dict__  # 将对象转成dict字典
    print(type(stu))  # <class 'dict'>
    print(stu)  # {'name': 'Joe.Ye', 'age': 28, 'sex': 'male', 'phone': '18800000000', 'email': 'test@test.com', 'id': 1}
    j = json.dumps(obj=stu)
    print(j)  # {"name": "Joe.Ye", "age": 28, "sex": "male", "phone": "18800000000", "email": "test@test.com", "id": 1}

# json数据转成dict字典
def json_to_dict():
    j = '{"id": 1, "name": "Joe.Ye", "age": 28, "sex": "male", "phone": "18800000000", "email": "test@test.com"}'
    dict = json.loads(s=j)
    print(dict)  # {u'name': u'Joe.Ye', u'age': 28, u'sex': u'male', u'phone': u'18800000000', u'email': u'test@test.com', u'id': 1}

# json数据转成对象
def json_to_obj():
    j = '{"id": 1, "name": "Joe.Ye", "age": 28, "sex": "male", "phone": "18800000000", "email": "test@test.com"}'
    dict = json.loads(s=j)
    stu = Student()
    stu.__dict__ = dict
    print('id: ' + str(stu.id) + ', name: ' + stu.name + ', age: ' + str(stu.age) + ', sex: ' + str(stu.sex) +
          ', phone: ' + stu.phone + ', email: ' + stu.email)  # id: 1, name: Joe.Ye, age: 28, sex: male, phone: 18800000000, email: test@test.com

class Student():
    # Python通过参数默认值方式实现构造函数重载
    def __init__(self, id=0, name='', age=0, sex='', phone='', email=''):
        self.id = id
        self.name = name
        self.age = age
        self.sex = sex
        self.phone = phone
        self.email = email

# dump()方法的使用
def dict_to_json_write_file():
    dict = {}
    dict['name'] = 'Joe.Ye'
    dict['age'] = 10
    dict['sex'] = 'male'
    print(dict)  # {'age': 10, 'name': 'Joe.Ye', 'sex': 'male'}
    with open('test.json', 'w') as f:
        json.dump(dict, f)  # 会在目录下生成一个test.json的文件，文件内容是dict数据转成的json数据

# load()方法的使用
def json_file_to_dict():
    with open('test.json', 'r') as f:
        dict = json.load(fp=f)
        print(dict)  # {u'age': 10, u'name': u'Joe.Ye', u'sex': u'male'}

if __name__ == '__main__':
    dict_to_json()
    obj_to_json()
    json_to_dict()
    json_to_obj()
    dict_to_json_write_file()
    json_file_to_dict()