How can I make a value becomes "NULL" where the API response have "missing subset&quo-CodePudding

I'm storing data from an API and for some response of different country, some of the subsets is not provided, thus when I tried to subset and use the .get() method it return KeyError.

I'm wondering how I can ignore these variable and return null value when the data is not provided by the API response.

Below is the json response of two different country: businessreport_ES.json

    "salesAndTrafficByAsin": [{
        "parentAsin": "AX0003",
        "childAsin": "AXC0001",
        "sku": "AXC1",
        "salesByAsin": {
            "unitsOrdered": 1,
            "orderedProductSales": {
                "amount": 31.06,
                "currencyCode": "EUR"
            },
            "totalOrderItems": 1
        },
        "trafficByAsin": {
            "browserSessions": 0,
            "mobileAppSessions": 1,
            "sessions": 1,
            "browserSessionPercentage": 0.0,
            "mobileAppSessionPercentage": 50.0,
            "sessionPercentage": 14.29,
            "browserPageViews": 0,
            "mobileAppPageViews": 9,
            "pageViews": 9,
            "browserPageViewsPercentage": 0.0,
            "mobileAppPageViewsPercentage": 90.0,
            "pageViewsPercentage": 56.25,
            "buyBoxPercentage": 100.0,
            "unitSessionPercentage": 100.0
        }]

businessreport_UK.json

    "salesAndTrafficByAsin": [{
        "parentAsin": "AX0003",
        "childAsin": "AXC0001",
        "sku": "AXC1",
        "salesByAsin": {
            "unitsOrdered": 0,
            "unitsOrderedB2B": 0,
            "orderedProductSales": {
                "amount": 0.0,
                "currencyCode": "GBP"
            },
            "orderedProductSalesB2B": {
                "amount": 0.0,
                "currencyCode": "GBP"
            },
            "totalOrderItems": 0,
            "totalOrderItemsB2B": 0
        },
        "trafficByAsin": {
            "browserSessions": 3,
            "browserSessionsB2B": 0,
            "mobileAppSessions": 12,
            "mobileAppSessionsB2B": 0,
            "sessions": 15,
            "sessionsB2B": 0,
            "browserSessionPercentage": 0.16,
            "browserSessionPercentageB2B": 0.0,
            "mobileAppSessionPercentage": 0.47,
            "mobileAppSessionPercentageB2B": 0.0,
            "sessionPercentage": 0.34,
            "sessionPercentageB2B": 0.0,
            "browserPageViews": 3,
            "browserPageViewsB2B": 0,
            "mobileAppPageViews": 15,
            "mobileAppPageViewsB2B": 0,
            "pageViews": 18,
            "pageViewsB2B": 0,
            "browserPageViewsPercentage": 0.12,
            "browserPageViewsPercentageB2B": 0.0,
            "mobileAppPageViewsPercentage": 0.46,
            "mobileAppPageViewsPercentageB2B": 0.0,
            "pageViewsPercentage": 0.31,
            "pageViewsPercentageB2B": 0.0,
            "buyBoxPercentage": 0.0,
            "buyBoxPercentageB2B": 0.0,
            "unitSessionPercentage": 0.0,
            "unitSessionPercentageB2B": 0.0
        }
    }]

Below is my code:

        f = open(f'./responses/businessreport_{marketplace}.json')
        jsondata = json.load(f)
        salesAndTrafficByAsin = []

        for item in jsondata['salesAndTrafficByAsin']:
            salesAndTrafficByAsin.append({
                "date": pd.to_datetime(datef),
                "parentAsin": item.get('parentAsin'),
                "childAsin": item.get('childAsin'),
                'unitsOrdered': item["salesByAsin"].get('unitsOrdered'),
                'unitsOrderedB2B': item["salesByAsin"].get('unitsOrderedB2B'),
                'orderedProductSales': item["salesByAsin"]['orderedProductSales'].get('amount'),
                'currencyCode': item["salesByAsin"]['orderedProductSales'].get('currencyCode'),
                'orderedProductSales_B2B': item["salesByAsin"]['orderedProductSalesB2B'].get('amount'),
                'currencyCode_B2B': item["salesByAsin"]['orderedProductSalesB2B'].get('currencyCode'),
                'browserSessions': item["trafficByAsin"].get('browserSessions'),
                "browserSessionsB2B": item["trafficByAsin"].get('browserSessionsB2B'),
                "mobileAppSessions": item["trafficByAsin"].get('mobileAppSessions'),
                "mobileAppSessionsB2B": item["trafficByAsin"].get('mobileAppSessionsB2B'),
                "sessions": item["trafficByAsin"].get('sessions'),
                "sessionsB2B": item["trafficByAsin"].get('sessionsB2B'),
                "browserSessionPercentage": item["trafficByAsin"].get('browserSessionPercentage'),
                "browserSessionPercentageB2B": item["trafficByAsin"].get('browserSessionPercentageB2B'),
                "mobileAppSessionPercentage": item["trafficByAsin"].get('mobileAppSessionPercentage'),
                "mobileAppSessionPercentageB2B": item["trafficByAsin"].get('mobileAppSessionPercentageB2B'),
                "sessionPercentage": item["trafficByAsin"].get('sessionPercentage'),
                "sessionPercentageB2B": item["trafficByAsin"].get('sessionPercentageB2B'),
                "browserPageViews": item["trafficByAsin"].get('browserPageViews'),
                "browserPageViewsB2B": item["trafficByAsin"].get('browserPageViewsB2B'),
                "mobileAppPageViews": item["trafficByAsin"].get('mobileAppPageViews'),
                "mobileAppPageViewsB2B": item["trafficByAsin"].get('mobileAppPageViewsB2B'),
                "pageViews": item["trafficByAsin"].get('pageViews'),
                "pageViewsB2B": item["trafficByAsin"].get('pageViewsB2B'),
                "browserPageViewsPercentage": item["trafficByAsin"].get('browserPageViewsPercentage'),
                "browserPageViewsPercentageB2B": item["trafficByAsin"].get('browserPageViewsPercentageB2B'),
                "mobileAppPageViewsPercentage": item["trafficByAsin"].get('mobileAppPageViewsPercentage'),
                "mobileAppPageViewsPercentageB2B": item["trafficByAsin"].get('mobileAppPageViewsPercentageB2B'),
                "pageViewsPercentage": item["trafficByAsin"].get('pageViewsPercentage'),
                "pageViewsPercentageB2B": item["trafficByAsin"].get('pageViewsPercentageB2B'),
                "buyBoxPercentage": item["trafficByAsin"].get('buyBoxPercentage'),
                "buyBoxPercentageB2B": item["trafficByAsin"].get('buyBoxPercentageB2B'),



            })

So the difference here is that buesinessreport_UK.json have the orderedProductSalesB2B subset while buesinessreport_ES.json dont. So the code return the error as shown below when trying to loop the buesinessreport_ES.json data

     46 salesAndTrafficByDate = []
     47 for item in jsondata['salesAndTrafficByDate']:
     48     salesAndTrafficByDate.append({
     49         "date": pd.to_datetime(item.get('date')),
     50         "orderedProductSales": item["salesByDate"]['orderedProductSales'].get('amount'),
     51         "CurrencyCode": item["salesByDate"]['orderedProductSales'].get('currencyCode'),
---> 52         "orderedProductSales_B2B": item["salesByDate"]['orderedProductSalesB2B'].get('amount'),
     53         "CurrencyCode_B2B": item["salesByDate"]['orderedProductSalesB2B'].get('currencyCode'),
     54         "unitsOrdered": item["salesByDate"].get("unitsOrdered"),
     55         "unitsOrdered_B2B": item["salesByDate"].get("unitsOrderedB2B"),
     56         "totalOrderItems": item["salesByDate"].get("totalOrderItems"),
     57         "totalOrderItems_B2B": item["salesByDate"].get("totalOrderItemsB2B"),
     58         "averageSalesPerOrderItem": item["salesByDate"]["averageSalesPerOrderItem"].get("amount"),
     59         "averageSalesPerOrderItem_B2B": item["salesByDate"]["averageSalesPerOrderItemB2B"].get("amount"),
     60         "averageUnitsPerOrderItem": item["salesByDate"].get("averageUnitsPerOrderItem"),
     61         "averageUnitsPerOrderItem_B2B": item["salesByDate"].get("averageUnitsPerOrderItem"),
     62         "averageSellingPrice": item["salesByDate"]["averageSellingPrice"].get("amount"),
     63         "averageSellingPrice_B2B": item["salesByDate"]["averageSellingPriceB2B"].get("amount"),
     64         "unitsRefunded": item["salesByDate"].get("unitsRefunded"),
     65         "refundRate": item["salesByDate"].get("refundRate"),
     66         "claimsGranted": item["salesByDate"].get("claimsGranted"),
     67         "claimsAmount": item["salesByDate"]["claimsAmount"].get("amount"),
...
     71     })
     72 salesAndTrafficByAsin = []
     74 for item in jsondata['salesAndTrafficByAsin']:

KeyError: 'orderedProductSalesB2B'

CodePudding user response：

Imho you should use multiple gets chained, cause that's what they were designed for i.a.

I wouldn't recommend it to be honest, but you can define a method to "safely" get values from a nested dictionary.

loop over "nested keys"
reassign the result
return the result OR default if the key is not present at some level of nesting

def nested_get(d, *keys, default=None):
  """
  Return value from nested dictionary
  nested_get(d, "a","b") == d["a"]["b"]
  """
  for k in keys:
    try:
      d = d[k]
    except (TypeError, ValueError):
      return default
  return d

a = {"w":{"d":5}}
b = {"x":{"D": 5}}
value = nested_get(b,"x","D")
print(value) # This prints 5
value = nested_get(a,"w","d","t")
print(value) # This prints "None"
value = nested_get(a,"w","d","t", default = 11)
print(value) # This prints 11