将JSON字符串转换为字典对象

Question

我已经能够调用一个api并获得响应，但是在将JSON字符串转换为Python字典对象时遇到了麻烦，因此我可以通过它进行解析。

JSON字符串示例：

{
  "target": {
    "icao_address": "C032A2",
    "timestamp": "2020-02-13T22:44:39Z",
    "latitude": 50.723694,
    "longitude": -114.63788,
    "altitude_baro": 13225,
    "heading": 40.0,
    "ground_speed": 340.0,
    "vertical_rate": -2360,
    "squawk_code": "6616",
    "on_ground": false,
    "callsign": "WEN3627",
    "tail_number": "C-FTEN",
    "collection_type": "terrestrial",
    "flight_number": "WR3627",
    "origin_airport_iata": "PDX",
    "destination_airport_iata": "YYC"
  }
}{
  "target": {
    "icao_address": "AB35D8",
    "timestamp": "2020-02-13T22:44:42Z",
    "latitude": 33.69842,
    "longitude": -111.896725,
    "altitude_baro": 4325,
    "heading": 260.0,
    "ground_speed": 90.0,
    "vertical_rate": -250,
    "on_ground": false,
    "callsign": "MSQT356",
    "tail_number": "N821PA",
    "collection_type": "terrestrial"
  }
}{

我正在使用的代码，我可以通过打开JSON字符串的文件来打印出JSON字符串，但无法将其作为字典进行访问。理想情况下，我只是想计算JSON字符串中不同字典的数量。

    #call datastream and output to new file
    def call_stream(self):
        try:
            #paramaters for call
            headers = {'Content-Type': 'application/json','Authorization': 'Bearer {0}'.format(self.token)}
            timeout = time.time() + self.timeout

            #calling datastream
            with requests.get(self.url, headers=headers, stream=True) as r:
                with open('datastream:' + self.get_time() + '.json', 'w') as json_file:
                    global target_updates_count
                    global terrestrial_count
                    global satellite_count
                    global FILENAME
                    FILENAME.append(json_file.name)

                    #reading through JSON hashtables
                    for line in r.iter_lines(decode_unicode=True):
                        target_updates_count += 1
                        if time.time() < timeout:
                            msg = json.loads(line)
                            json_pprint = json.dumps(msg)
                            json_file.write(json_pprint)

                            #looping through dict objects and counting useful statistics for target_updates
                            data = msg['target']
                            for key in data:
                                if key == 'collection_type' and data[key] == 'terrestrial':
                                    terrestrial_count += 1
                                elif key == 'collection_type' and data[key] == 'satellite':
                                    satellite_count += 1
                        else:
                            r.close()
        except AttributeError:
            pass