Json中datatime問題

from datetime import datetime
from functools import singledispatch

dict = {"name":"小明","age":18,"height":180,'time':datetime.now()}


class MyEncoder(json.JSONEncoder):

    def default(self, o):
        try:
            return Jsondispatch.encode(o)
        except TypeError:
            return super().default(self, o)

class Jsondispatch:

    @singledispatch
    def encode(o):
        raise TypeError("Unencode type")

    @encode.register(datetime)
    def _(o):
        return '{}'.format(o.strftime('%Y-%m-%d %H:%M:%S'))



a = json.dumps(dict,cls=MyEncoder,ensure_ascii=False)
print(a)
print(type(a))
b = json.loads(a)
print(b)
print(type(b))

{"name": "小明", "age": 18, "height": 180, "time": "2020-05-26 00:12:37"}
<class 'str'>
{'name': '小明', 'age': 18, 'height': 180, 'time': '2020-05-26 00:12:37'}
<class 'dict'>

只要被singledispatch 裝飾的函數，就是一個單分派的（single-dispatch ）的泛函數（generic functions）。單分派：根據一個參數的類型，以不同方式執行相同的操作的行爲。