Python-Django的JsonResponse對象詳解

----小編在寫項目的時候,發現django的JsonResponse很難搞,就上網上搜,但是搜來搜去發現每個都不全面,所以小編在這就整理了一下,希望能給你帶來幫助

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三個方面入手:

• 參數(self, data,  encoder=DjangoJSONEncoder,  safe=True, json_dumps_params=None, **kwargs)
  • data:傳入的需要序列化的對象,默認是字典類型,  例:    JsonResponse(dict)
  • safe:默認值參數,當它爲true時,data只能是字典類型,爲false時,就可以爲任何可以轉換爲json格式的對象(list,tuble)
  • encoder:執行DjangoJSONEncoder類,這個類繼承(json.JSONEncoder),因爲json轉換的數據對象有限,所以DjangoJSONEncoder重寫了defalut方法,裏面進行對時間對象的轉換成json格式;
  • json_dumps_params:參數是一個字典,它將調用json.dums,並將參數傳給該方法,也就是調用原來json的本身的參數和方法;
• 返回值
  • return super(DjangoJSONEncoder, self).default(o)
• 核心思想:
  • 本身繼承json.JSONEncoder,因爲JSONEncoder可轉換的數據格式有限,所以DjangoJSONEncoder重寫了default方法,該方法裏對時間對象進行了轉換,而json_dumps_params可以給本身dumps傳入參數\
• 源碼:

• def __init__(self, data, encoder=DjangoJSONEncoder, safe=True,
                   json_dumps_params=None, **kwargs):
      if safe and not isinstance(data, dict):
        raise TypeError(
             'In order to allow non-dict objects to be serialized set the '
             'safe parameter to False.'
           )
      if json_dumps_params is None:
            json_dumps_params = {}
            kwargs.setdefault('content_type', 'application/json')
            data = json.dumps(data, cls=encoder, **json_dumps_params)
            super(JsonResponse, self).__init__(content=data, **kwargs)

  class DjangoJSONEncoder(json.JSONEncoder):
      """
      JSONEncoder subclass that knows how to encode date/time, decimal types and UUIDs.
      """
      def default(self, o):
          # See "Date Time String Format" in the ECMA-262 specification.
          if isinstance(o, datetime.datetime):
              r = o.isoformat()
              if o.microsecond:
                  r = r[:23] + r[26:]
              if r.endswith('+00:00'):
                  r = r[:-6] + 'Z'
              return r
          elif isinstance(o, datetime.date):
              return o.isoformat()
          elif isinstance(o, datetime.time):
              if is_aware(o):
                  raise ValueError("JSON can't represent timezone-aware times.")
              r = o.isoformat()
              if o.microsecond:
                  r = r[:12]
              return r
          elif isinstance(o, datetime.timedelta):
              return duration_iso_string(o)
          elif isinstance(o, decimal.Decimal):
              return str(o)
          elif isinstance(o, uuid.UUID):
              return str(o)
          elif isinstance(o, Promise):
              return six.text_type(o)
          elif isinstance(o, CallableBool):
              return bool(o)
          else:
              return super(DjangoJSONEncoder, self).default(o)