你如何从 json 中提取值来重复

Question

我有这个 json 文件：

{
  "totalCount": 10,
  "nextPageKey": null,
  "result": [
    {
      "metricId": "builtin:host.cpu.system:",
      "data": [
        {
          "dimensions": [
            "host13"
          ],
          "dimensionMap": {
            "dt.entity.host": "host13"
          },
          "timestamps": [
            1643131800000,
            1643132400000,
            1643133000000,
            1643133600000,
            1643134200000,
            1643134800000,
            1643135400000,
            1643136000000,
            1643136600000,
            1643137200000,
            1643137800000,
            1643138400000,
            1643139000000
          ],
          "values": [
            1.3207547664642334,
            2.684309959411621,
            2.9341392517089844,
            2.646502733230591,
            3.0115926265716553,
            5.730949878692627,
            2.8099799156188965,
            1.348116397857666,
            1.687232494354248,
            2.947845697402954,
            1.4364919662475586,
            1.7499685287475586,
            3.0505483150482178
          ]
        },
        {
          "dimensions": [
            "host234"
          ],
          "dimensionMap": {
            "dt.entity.host": "host234"
          },
          "timestamps": [
            1643131800000,
            1643132400000,
            1643133000000,
            1643133600000,
            1643134200000,
            1643134800000,
            1643135400000,
            1643136000000,
            1643136600000,
            1643137200000,
            1643137800000,
            1643138400000,
            1643139000000
          ],
          "values": [
            1.3899515867233276,
            3.487347364425659,
            3.2599117755889893,
            2.5915210247039795,
            2.971543788909912,
            5.280444622039795,
            1.863745093345642,
            3.30224347114563,
            1.6360433101654053,
            3.5056746006011963,
            4.327470779418945,
            2.026176691055298,
            3.5184237957000732
          ]
        },
        {
          "dimensions": [
            "host9000"
          ],
          "dimensionMap": {
            "dt.entity.host": "host9000"
          },
          "timestamps": [
            1643131800000,
            1643132400000,
            1643133000000,
            1643133600000,
            1643134200000,
            1643134800000,
            1643135400000,
            1643136000000,
            1643136600000,
            1643137200000,
            1643137800000,
            1643138400000,
            1643139000000
          ],
          "values": [
            1.6770082712173462,
            3.380143642425537,
            2.664911985397339,
            3.472454071044922,
            3.053309202194214,
            4.846103668212891,
            1.625740885734558,
            3.096479892730713,
            1.6604264974594116,
            3.3423821926116943,
            1.8394920825958252,
            2.470339775085449,
            2.6470096111297607
          ]
        },
        {
          "dimensions": [
            "host777"
          ],
          "dimensionMap": {
            "dt.entity.host": "host777"
          },
          "timestamps": [
            1643131800000,
            1643132400000,
            1643133000000,
            1643133600000,
            1643134200000,
            1643134800000,
            1643135400000,
            1643136000000,
            1643136600000,
            1643137200000,
            1643137800000,
            1643138400000,
            1643139000000
          ],
          "values": [
            1.409336805343628,
            2.9157116413116455,
            3.176203727722168,
            2.773225784301758,
            2.760272264480591,
            4.695191383361816,
            2.698251724243164,
            3.1021218299865723,
            2.0791330337524414,
            3.1175060272216797,
            2.448374032974243,
            2.5085086822509766,
            3.1482181549072266
          ]
        },
        {
          "dimensions": [
            "host999"
          ],
          "dimensionMap": {
            "dt.entity.host": "host999"
          },
          "timestamps": [
            1643131800000,
            1643132400000,
            1643133000000,
            1643133600000,
            1643134200000,
            1643134800000,
            1643135400000,
            1643136000000,
            1643136600000,
            1643137200000,
            1643137800000,
            1643138400000,
            1643139000000
          ],
          "values": [
            1.3565394878387451,
            3.0833122730255127,
            2.405238628387451,
            2.5759658813476562,
            2.4040277004241943,
            4.598429203033447,
            2.5394818782806396,
            3.2278401851654053,
            1.499437689781189,
            3.1490111351013184,
            3.756218910217285,
            3.3754220008850098,
            2.418745279312134
          ]
        },
        {
          "dimensions": [
            "Host111"
          ],
          "dimensionMap": {
            "dt.entity.host": "Host111"
          },
          "timestamps": [
            1643131800000,
            1643132400000,
            1643133000000,
            1643133600000,
            1643134200000,
            1643134800000,
            1643135400000,
            1643136000000,
            1643136600000,
            1643137200000,
            1643137800000,
            1643138400000,
            1643139000000
          ],
          "values": [
            1.4735431671142578,
            3.3221476078033447,
            3.101944923400879,
            2.8839704990386963,
            4.312218189239502,
            1.8795099258422852,
            1.5133275985717773,
            3.0394625663757324,
            1.683100938796997,
            2.910053014755249,
            1.5296052694320679,
            1.9281476736068726,
            2.5355799198150635
          ]
        }
        
      ]
    }
  ]
}

我需要从这个 json 文件字段“维度”、“时间戳”和“值”中创建一个数据框

dimensions  timestamps  values
host13  1.64313E+12 1.320754766
host13  1.64313E+12 2.684309959
host13  1.64313E+12 2.934139252
host13  1.64313E+12 2.646502733

我试过这个：

dataList = []
dataList.append([resp['data']['dimensions'], resp['data']['timestamp'],resp['data']['values']])

数据框不工作？ 有任何想法吗？

Answer 1

使用pd.json_normalize以获得更好的性能。

df = pd.json_normalize(data, record_path=['result', 'data'])[['dimensions', 'timestamps', 'values']]

# Then explode the list into rows
df = df.explode('dimensions').explode('timestamps').explode('values')

# If pandas version 1.3+
df = df.explode(['dimensions', 'timestamps', 'values'])

Answer 2

您需要迭代每个数据，并为每个timestamps和值的values

dataList = []
for item in data['result'][0]['data']:
    for timestamp, value in zip(item["timestamps"], item["values"]):
        dataList.append((item["dimensions"][0], timestamp, value))

df = pd.DataFrame(dataList, columns=["dimensions", "timestamps", "values"])

---

使用itertools.repeat你可以在一个很好的列表理解中缩短它

from itertools import repeat
dataList = [zip(repeat(item["dimensions"][0]), item["timestamps"], item["values"])
            for item in data['result'][0]['data']]