How to change 'data' of all the values in key-value pair in JSON?

I have a JSON data which is:

json_string = '[
  {
    "degree": "masters",
    "school": "PU",
    "joinedOn": {
      "year": 2021,
      "month": "FEB"
    },
    "address": [
      {
        "b_Address": "UK",
        "city": "London"
      },
      {
        "b_Address": "US",
        "city": "Texas"
      }
    ],
    "fieldOfStudy": "MBA",
    "levelOfEducation": "MASTER",
    "currentlyStudying": "true"
  }
]' 

I want to change the data of every keys like this:

   {
  "degree": "5pcBBS07",
  "school": "ZozkeyAV",
  "joinedOn": "y5cO3L9i",
  "address": "mBa3oqMs",
  "fieldOfStudy": "MBA",
  "levelOfEducation": "MASTER",
  "currentlyStudying": "true"
}    

Here the values of "degree", "school","phone","joinedOn","address" has been changed. Buy my expectation was since "joinedOn" has an object but the output is coming as:

"joinedOn": "y5cO3L9i"   

I want the output to be:

"joinedOn": {
          "year": XYZ,
          "month": "ABC"
        }

Same case goes for "address". I am just getting single value "mBa3oqMs", I want the output to be:

  "address": [
          {
            "b_Address": "ABC",
            "city": "DEF"
          },
          {
            "b_Address": "GHI",
            "city": "JKL"
          }
        ]

I tired as:

json_string = '[{"degree": "masters", "school": "PU", "joinedOn": {"year": 2021, "month": "FEB"}, "address": [{"b_Address": "UK", "city": "London"},{"b_Address": "US", "city": "Texas"}], "fieldOfStudy": "MBA","levelOfEducation": "MASTER","currentlyStudying": "true"}]'
        
data = load_json_data(json_string)

if data:
    fields_to_anonymize = ["degree", "school","phone","joinedOn","address"]
    anonymized_data = anonymize_json_data(data[0], fields_to_anonymize)

    # Alternatively, convert it back to a string
    anonymized_json_string = json.dumps(anonymized_data)
    print(anonymized_json_string)

Loading JSON file:

def load_json_data(json_string):
    try:
        data = json.loads(json_string)
        return data
    except json.JSONDecodeError as e:
        print("Error parsing JSON:", str(e))
        return None

Changing the values:

def anonymize_json_data(data, fields_to_anonymize):
    for field in fields_to_anonymize:
        if field in data:
            data[field] = generate_random_string()
    return data

def generate_random_string(length=8):
    letters_and_digits = string.ascii_letters + string.digits
    return ''.join(random.choice(letters_and_digits) for _ in range(length))

How can I get the output where key will have object and the object will have their own changed data?

Your code is not working because you are ignoring the fact that some values of the dictionary can be of type dict or list

You should change your code to handle that, Check the below code with the required changes

def randomize(data):
    if isinstance(data, dict):
        return {key: generate_random_string() for key, value in data.items()}
    elif isinstance(data, list):
        return [randomize(x) for x in data]
    return data

def anonymize_json_data(data, fields_to_anonymize):
    for key, value in data.items():
        if isinstance(value, (dict, list)) and key in fields_to_anonymize:
            data[key] = randomize(value)       
        elif key in fields_to_anonymize:
            data[key] = generate_random_string() 
    return data

With this change you will be able to get the output in the expected format
Output:

{'degree': '85SovY6B',
 'school': 'D6YBpJDB',
 'joinedOn': {'year': 'ggbmvYEd', 'month': 'ZUoJOO6A'},
 'address': [{'b_Address': 'F6w5Qwsh', 'city': 'Xnz1pDbg'},
             {'b_Address': '1zjZ0mLw', 'city': 'ofB677lP'}],
 'fieldOfStudy': 'MBA',
 'levelOfEducation': 'MASTER',
 'currentlyStudying': 'true'}