How do I update my dictionary with values from JSON?

I want to update my dictionary with values from the json_file which is of type dict. Here is the JSON dictionary format that I am working with.

  json_file:  {
      "appointmentDeltaEmployee": {
        "SSN": "XXXXXXXX",
        "dutyBasis": "1",
        "normalHours": 80
      },
      "deductionsDeltaEmployee": {
        "unionDuesAnniversaryDay": null,
        "DFASUnionCode": null
      },
      "followUpDeltaEmployee": [
        {
          "noac05followUpCode": null,
          "followUpCode": "S2",
          "followUpDate": "2019-10-01"
        }
      ],
      "laborDetailsDeltaEmployee": [
        {
          "functionalCode": "00",
          "fundControlPointFor1stPosition": "001",
          "cityTaxSatellite": null,
          "fMSFundCode": "012012",
          "primaryLaborCodePercentage": 100,
          "laborDistributionCode": "BBBB",
          "laborcostcenter": "5555"
        }
      ],
      "leaveDetailsDeltaEmployee": {
        "disabledVeteranLeave": "N",
        "leaveGroup": "2",
        "leaveRestriction": "N",
        "eligibleForLeaveNextPayPeriod": "N"
      }
    }

As you can see there are 2 keys that have list of dictionary. I need to maintain a specific order for output so I created an ordered dictionary with None values.

ordered_keys = ("leaveGroup", "functionalCode", "DFASUnionCode", "normalHours")

order_dic_keys = OrderedDict((k, None) for k in ordered_keys)

If I print my order_dic_keys this is what I get

OrderedDict([('leaveGroup', None), ('functionalCode', None), ('DFASUnionCode', None), ('normalHours', None)])

I want to use a for loop and update order_dic_keys and add the values of what is in the json_file. This is where I get lost and hit the list of dictionary.

for key in order_dic_keys.keys():
        for key2, values in json_file.items(): # key2 is followUpDeltaEmployee, values is [{u'followUpDate': u'2019-10-01', u'noac05followUpCode': None, u'followUpCode': u'S2'}]
            if key in json_file.items():
                order_dic_keys.update(json_file[values])

My order_dic_keys doesn't get updated. Do I parse out the list and create another dictionary with just key and value pairs? Am I not able to update because I used a tuple to maintain order?

Solution 1:

Instead of processing the data after it has been loaded - you can pass custom functions to json.load / loads which can simplify extraction:

ordered_keys = ("leaveGroup", "functionalCode", "DFASUnionCode", "normalHours")
order_dic_keys = OrderedDict.fromkeys(ordered_keys)

def extract_data(obj):
    for key, value in obj:
        if key in order_dic_keys:
            order_dic_keys[key] = value

>>> json.loads(data, object_pairs_hook=extract_data)
>>> order_dic_keys
OrderedDict([('leaveGroup', '2'),
             ('functionalCode', '00'),
             ('DFASUnionCode', None),
             ('normalHours', 80)])

full code example:

import json
from   collections import OrderedDict

def extract_data(obj):
    for key, value in obj:
        if key in order_dic_keys:
            order_dic_keys[key] = value
    return dict(obj)

ordered_keys = ("leaveGroup", "functionalCode", "DFASUnionCode", "normalHours")
order_dic_keys = OrderedDict.fromkeys(ordered_keys)

with open("file.json") as f:
    json_file = json.load(f, object_pairs_hook=extract_data)

print(order_dic_keys)