python 自定义对象list转json字符串怎么转？我试了很多方法
现象就是这样
这是代码
coding=utf-8
import json
class Demo(json.JSONEncoder):
def init(self,af,age):
self.af = af
self.age = age
list =[Demo("dfdf","ff"),Demo("fdsf","fgg")]
print json.dumps(list)
运行结果及报错内容
Traceback (most recent call last):
File "D:/pycharm/pythonDemo/Demo.py", line 10, in
print json.dumps(list)
File "D:\python\lib\json_init_.py", line 244, in dumps
return _default_encoder.encode(obj)
File "D:\python\lib\json\encoder.py", line 207, in encode
chunks = self.iterencode(o, _one_shot=True)
File "D:\python\lib\json\encoder.py", line 270, in iterencode
return _iterencode(o, 0)
File "D:\python\lib\json\encoder.py", line 184, in default
raise TypeError(repr(o) + " is not JSON serializable")
TypeError: <__main__.Demo object at 0x00000000031C8F48> is not JSON serializable
我的解答思路和尝试过的方法
鄙人尝试了很多方法都不行
我想要达到的结果
[{"af":"dfsf","age":"ffg"},{"af":"dfsf","age":"ffg"}]
demo类无法序列化，是因为默认情况下，dumps()方法不知道如何将Demo实例变为一个JSON的{}对象。
参考：
https://blog.csdn.net/mr_hui_/article/details/82941199
import json
class Demo(json.JSONEncoder):
def __init__(self,af,age):
self.af = af
self.age = age
print(json.dumps(list,default=lambda o: o.__dict__))
通过dumps的default传参可以实现对象的json化
default(obj)`` is a function that should return a serializable version
of obj or raise TypeError. The default simply raises TypeError.
向default内传入一个函数用于解析对象的键值对用以序列化成json字符串
# coding=utf-8
import json
class Demo(json.JSONEncoder):
def __init__(self, af, age):
self.af = af
self.age = age
# 自定义函数用以转换对象为字典函数
def objtodic(x):
# 将传入对象转换成字典,使用内置函数 __dict__
return x.__dict__
list = [Demo("dfdf", "ff"), Demo("fdsf", "fgg")]
print(json.dumps(list, default=objtodic))
import json
class Demo():
def __init__(self,af,age):
self.af = af
self.age = age
class DemoEncoder(json.JSONEncoder):
def default(self,obj):
d = {}
d.update(obj.__dict__)
return d
list =[Demo("dfdf","ff"),Demo("fdsf","fgg")]
print (json.dumps(list,cls=DemoEncoder))