Sum up how many fields are empty or do not exist in a dict

I have a problem. I have a list myList inside these list, there a dictonaries. I want to count if the field dataOriginSystem is empty or does not exist. Unfortunately I got the wrong result. if(key_nested == 'dataOriginSystem'): ... else: count =+ 1

The reason for this lies in the if-query. Since I am asking, does the field exist? If no, then count it up and since I loop through all the nested keys, one of the errors is here. Also, is there a way to make this more efficient?

How can I query how many of the field dataOriginSystem are empty or non-existent?

count = 0
for element in myList:
    for key in element.keys():
        if(key == 'metaData'):
            for key_nested in element[key].keys(): 
                if(key_nested == 'dataOriginSystem'):
                    if(key_nested == None):
                        count += 1
                else:
                    count += 1
print(count)

myList = [
{'_id': 'orders/213123',
 'contactEditor': {'name': 'Max Power',
  'phone': '1234567',
  'email': 'max@power.com'},
 'contactSoldToParty': {'name': 'Max Not',
  'phone': '123456789',
  'email': 'maxnot@power.com'},
 'isCompleteDelivery': False,
 'metaData': {'dataOriginSystem': 'Goods',
  'dataOriginWasCreatedTime': '10:12:12',},
 'orderDate': '2021-02-22',
 'orderDateBuyer': '2021-02-22',
},
{'_id': 'orders/12323',
 'contactEditor': {'name': 'Max Power2',
  'phone': '1234567',
  'email': 'max@power.com'},
 'contactSoldToParty': {'name': 'Max Not',
  'phone': '123456789',
  'email': 'maxnot@power.com'},
 'isCompleteDelivery': False,
 'metaData': {'dataOriginSystem': 'Goods',
  'dataOriginWasCreatedTime': '10:12:12',},
 'orderDate': '2021-02-22',
 'orderDateBuyer': '2021-02-22',
 },
{'_id': 'orders/12323',
 'contactEditor': {'name': 'Max Power2',
  'phone': '1234567',
  'email': 'max@power.com'},
 'contactSoldToParty': {'name': 'Max Not',
  'phone': '123456789',
  'email': 'maxnot@power.com'},
 'isCompleteDelivery': False,
 'metaData': {
  'dataOriginWasCreatedTime': '10:12:12',},
 'orderDate': '2021-02-22',
 'orderDateBuyer': '2021-02-22',
 },
{'_id': 'orders/12323',
 'contactEditor': {'name': 'Max Power2',
  'phone': '1234567',
  'email': 'max@power.com'},
 'contactSoldToParty': {'name': 'Max Not',
  'phone': '123456789',
  'email': 'maxnot@power.com'},
 'isCompleteDelivery': False,
 'metaData': {'dataOriginSystem': None,
  'dataOriginWasCreatedTime': '10:12:12',},
 'orderDate': '2021-02-22',
 'orderDateBuyer': '2021-02-22',
 },
]

Result should be

[OUT] 2
# Because of the two last elements.
# The first element does not exist
# and the second ist None. 

>Solution :

You don’t have to loop through the keys. Access the item you want directly and increment the counter if the item is not found, or found but None.

count = 0
for element in myList:
    if element["metaData"].get("dataOriginSystem", None) is None:
        count += 1
print(count)