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Question

Мне нужно подсчитать, сколько Mac-адресов имеют ухудшения на уровне документов

Я пытался обойти этот фильтр из другого примера на этом сайте, но проблема в том, что мне нужно подсчитать, сколько MAC-адресов имеетимя нарушения "docsis-level"

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    "timestamp": "2019-05-06T06:06:13.568Z",
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        "impaired": false,
        "startFrequency": 621,
        "stopFrequency": 621,
        "level": 0
      },
      {
        "name": "uncorrectable-cer",
        "impaired": false,
        "startFrequency": 621,
        "stopFrequency": 621,
        "level": 0
      },
      {
        "name": "docsis-snr",
        "impaired": false,
        "startFrequency": 639,
        "stopFrequency": 639,
        "level": 37.3
      },
      {
        "name": "docsis-level",
        "impaired": false,
        "startFrequency": 615,
        "stopFrequency": 615,
        "level": 11.6
      }
    ],
    "ofdmData": {
      "numChannels": 0,
      "numProfiles": 0
    }
  },
  {
    "mac": "B0:39:56:4B:B1:F8",
    "timestamp": "2019-05-06T05:05:34Z",
    "impairments": [
      {
        "name": "channel-snr",
        "impaired": false,
        "startFrequency": 669,
        "stopFrequency": 669,
        "level": 0
      },
      {
        "name": "channel-level",
        "impaired": false,
        "startFrequency": 669,
        "stopFrequency": 669,
        "level": 0
      },
      {
        "name": "channel-tilt",
        "impaired": false,
        "startFrequency": 669,
        "stopFrequency": 669,
        "level": 0
      },
      {
        "name": "channel-icfr",
        "impaired": false,
        "startFrequency": 669,
        "stopFrequency": 669,
        "level": 0
      },
      {
        "name": "channel-guard-band",
        "impaired": false,
        "startFrequency": 669,
        "stopFrequency": 669,
        "level": 0
      },
      {
        "name": "correctable-cer",
        "impaired": false,
        "startFrequency": 669,
        "stopFrequency": 669,
        "level": 0
      },
      {
        "name": "uncorrectable-cer",
        "impaired": false,
        "startFrequency": 669,
        "stopFrequency": 669,
        "level": 0
      },
      {
        "name": "docsis-snr",
        "impaired": false,
        "startFrequency": 675,
        "stopFrequency": 675,
        "level": 39.4
      },
      {
        "name": "docsis-level",
        "impaired": false,
        "startFrequency": 811,
        "stopFrequency": 904.95,
        "level": 4.4
      },
      {
        "name": "ofdm-mer-mean",
        "impaired": false,
        "startFrequency": 811,
        "stopFrequency": 904.95,
        "level": 39.44
      },
      {
        "name": "ofdm-mer-sd",
        "impaired": false,
        "startFrequency": 811,
        "stopFrequency": 904.95,
        "level": 0.61
      },
      {
        "name": "ofdm-amp-mean",
        "impaired": false,
        "startFrequency": 811,
        "stopFrequency": 904.95,
        "level": -0.13
      },
      {
        "name": "ofdm-amp-rms",
        "impaired": false,
        "startFrequency": 811,
        "stopFrequency": 904.95,
        "level": 0.72
      },
      {
        "name": "ofdm-amp-slope",
        "impaired": false,
        "startFrequency": 811,
        "stopFrequency": 904.95,
        "level": 0.004
      },
      {
        "name": "ofdm-amp-pk-pk",
        "impaired": false,
        "startFrequency": 811,
        "stopFrequency": 904.95,
        "level": 3.42
      },
      {
        "name": "ofdm-gd-mean",
        "impaired": false,
        "startFrequency": 811,
        "stopFrequency": 904.95,
        "level": 1851
      },
      {
        "name": "ofdm-gd-rms",
        "impaired": false,
        "startFrequency": 811,
        "stopFrequency": 904.95,
        "level": 8.59
      },
      {
        "name": "ofdm-gd-slope",
        "impaired": false,
        "startFrequency": 811,
        "stopFrequency": 904.95,
        "level": 0.026
      },
      {
        "name": "ofdm-gd-pk-pk",
        "impaired": false,
        "startFrequency": 811,
        "stopFrequency": 904.95,
        "level": 58.58
      },
      {
        "name": "ofdm-plc-cwer",
        "impaired": false,
        "startFrequency": 811,
        "stopFrequency": 904.95,
        "level": 0
      },
      {
        "name": "ofdm-ncp-fail",
        "impaired": false,
        "startFrequency": 811,
        "stopFrequency": 904.95,
        "level": 0
      }
    ],
    "ofdmData": {
      "numChannels": 1,
      "numProfiles": 4
    }
  }
]

Количество mac с уровнем docsis = x number

Answer 1

Я загрузил ваш файл json в "http://www.json -generator.com / api / json / get / cggsimUEBK? Indent = 2 ", и приведенный ниже код должен подсчитать количество.Просто запустите это в вашей консоли разработчика.

function findCount(){  
  var result = json.responseJSON;
  var count=0;
  result.forEach(function(item){
   var impairments = item.impairments;
     impairments.forEach(function(impairment){
        if((impairment['name'] == "docsis-level")){ count++;}
     });
   });
  console.log(count);
  alert(count);  
}
var json = $.getJSON("http://www.json-generator.com/api/json/get/cggsimUEBK?indent=2",findCount);

Answer 2

Самый простой способ подсчитать в jq - это использовать функцию для этой цели:

def count(stream): reduce stream as $i (0; .+1);

Это определение также поддерживает решения, эффективные как во времени, так и в пространстве.

Так как JSON в вопросе плохо сформирован, я предложу два решения - одно на основе объектов с «поврежденным» ключом:

count(.. | objects | select( has("impaired") and .name == "docsis-level"))

и другие, основанные на массивах "ухудшений":

count(.. | .impairments? // empty | .[] | select( .name? == "docsis-level"))

Эти два запроса иллюстрируют разные стили достижения различной степени устойчивости, но оба они не зависят от того, где соответствующие объекты находятся на входе.

Добавление

Теперь, когда пример данных был пересмотрен, может быть предложено следующее решение, которое зависит от регулярной структуры:

count(.[] | .impairments[] | select( .name == "docsis-level"))

Answer 3

позвольте мне предложить вам решение, основанное на Unix-инструменте Walk-Path для JSON: jtc - там вы «кодируете» логику запроса прямо в путь.

1. ваш JSON немного искажен (вы можете использовать jtc -d, чтобы увидеть местоположение проблемы в опубликованном JSON)

2. после исправления JSON этот cli будет считать все MAC, где impairments содержит запись "name": "docsis-level":

bash $ <file.json jtc -w'<mac>l:[-1] [impairments][name]:<docsis-level>' -r | wc -l
       8
bash $ 

Объяснение дорожки (-w):

• <mac>l:[-1] - найти каждую запись с меткой mac и шагом 1 уровня (в JSON) от найденной записи
• [impairments][name]:<docsis-level> - адресная запись impairments и найти там запись "name": "docsis-level"
• если все вышеперечисленные шаги пройдены успешно - выведите найденную запись

wc -l будет считать собранные (успешные) прогулки

PS> Раскрытие информации: я создатель инструмента jtc