How to Parsing Nested Json with Python?

I am trying to parse this nested JSON file and I am running having trouble getting every element I need.

Here is the json example:

    {
  "sensor-time" : {
    "timezone" : "New_York",
    "time" : "2020-07-15T12:45:02-04:00"
  },
  "status" : {
    "code" : "OK"
  },
  "content" : {
    "element" : [ {
      "element-id" : 0,
      "element-name" : "Line 0",
      "sensor-type" : "SINGLE_SENSOR",
      "data-type" : "LINE",
      "from" : "2020-07-15T12:30:00-04:00",
      "to" : "2020-07-15T12:45:00-04:00",
      "resolution" : "FIVE_MINUTES",
      "measurement" : [ {
        "from" : "2020-07-15T12:30:00-04:00",
        "to" : "2020-07-15T12:35:00-04:00",
        "value" : [ {
          "value" : 1,
          "label" : "fw"
        }, {
          "value" : 2,
          "label" : "bw"
        } ]
      }, {
        "from" : "2020-07-15T12:35:00-04:00",
        "to" : "2020-07-15T12:40:00-04:00",
        "value" : [ {
          "value" : 3,
          "label" : "fw"
        }, {
          "value" : 4,
          "label" : "bw"
        } ]
      }, {
        "from" : "2020-07-15T12:40:00-04:00",
        "to" : "2020-07-15T12:45:00-04:00",
        "value" : [ {
          "value" : 5,
          "label" : "fw"
        }, {
          "value" : 6,
          "label" : "bw"
        } ]
      } ]
    }, {
      "element-id" : 1,
      "element-name" : "Test Line",
      "sensor-type" : "SINGLE_SENSOR",
      "data-type" : "LINE",
      "from" : "2020-07-15T12:30:00-04:00",
      "to" : "2020-07-15T12:45:00-04:00",
      "resolution" : "FIVE_MINUTES",
      "measurement" : [ {
        "from" : "2020-07-15T12:30:00-04:00",
        "to" : "2020-07-15T12:35:00-04:00",
        "value" : [ {
          "value" : 7,
          "label" : "fw"
        }, {
          "value" : 8,
          "label" : "bw"
        } ]
      }, {
        "from" : "2020-07-15T12:35:00-04:00",
        "to" : "2020-07-15T12:40:00-04:00",
        "value" : [ {
          "value" : 9,
          "label" : "fw"
        }, {
          "value" : 10,
          "label" : "bw"
        } ]
      }, {
        "from" : "2020-07-15T12:40:00-04:00",
        "to" : "2020-07-15T12:45:00-04:00",
        "value" : [ {
          "value" : 11,
          "label" : "fw"
        }, {
          "value" : 12,
          "label" : "bw"
        } ]
      } ]
    } ]
  },
  "sensor-info" : {
    "serial-number" : "D7:40:1:7F:4A:72",
    "ip-address" : "192.168.130.44",
    "name" : "DemoNew",
    "group" : "Internal Test Devices",
    "device-type" : "PC2"
  }
}

What I am trying to get is measurement data for each element name. Please see the example below:

Here is what I tried:

    data = {} # element-name ↦ direction ↦ {readings ↦ (timestamp × value) list, meta ↦ name ↦ value}
for element in json_data['content']['element']:
    element_name = element['element-name']
    element_data = {}

# collect
    for measurement in element['measurement']:
        dt = datetime.strptime(measurement['to'][:-3]+'00', '%Y-%m-%dT%H:%M:%S%z')
        t = mktime(dt.timetuple())

        for pair in measurement['value']:
            direction = pair['label']
            value     = pair['value']

            if not direction in element_data: element_data[direction] = []
            element_data[direction].append( (t, value) )

# insert
    metadata = {}
    for key in element:
        if not key in ['measurement', 'from', 'to']:
            metadata[key] = element[key]
    data[element_name] = {}
    for direction in element_data:
        data[element_name][direction] = {'readings': element_data[direction], 'meta': metadata}

camera_metadata = {}
for key in json_data:
    if not key in ['content']:
        camera_metadata[key] = json_data[key]

And her is what I get as result:

    {'Line 0': {'fw': {'readings': [(1594830900.0, 1),
    (1594831200.0, 3),
    (1594831500.0, 5)],
   'meta': {'element-id': 0,
    'element-name': 'Line 0',
    'sensor-type': 'SINGLE_SENSOR',
    'data-type': 'LINE',
    'resolution': 'FIVE_MINUTES'}},
  'bw': {'readings': [(1594830900.0, 2), (1594831200.0, 4), (1594831500.0, 6)],
   'meta': {'element-id': 0,
    'element-name': 'Line 0',
    'sensor-type': 'SINGLE_SENSOR',
    'data-type': 'LINE',
    'resolution': 'FIVE_MINUTES'}}},
 'GP Test CL.01': {'fw': {'readings': [(1594830900.0, 7),
    (1594831200.0, 9),
    (1594831500.0, 11)],
   'meta': {'element-id': 1,
    'element-name': 'GP Test CL.01',
    'sensor-type': 'SINGLE_SENSOR',
    'data-type': 'LINE',
    'resolution': 'FIVE_MINUTES'}},
  'bw': {'readings': [(1594830900.0, 8),
    (1594831200.0, 10),
    (1594831500.0, 12)],
   'meta': {'element-id': 1,
    'element-name': 'GP Test CL.01',
    'sensor-type': 'SINGLE_SENSOR',
    'data-type': 'LINE',
    'resolution': 'FIVE_MINUTES'}}}}

What do I need to adjust to get the result to look as a screenshot example above?