How To Remove Null Values from JSON in Python

In this tutorial, you’ll learn  various methods to remove Null values from JSON in Python

We’ll explore multiple methods, including dictionary comprehension, iteration & deletion, and handling nested JSON.

 

 

Using Dictionary Comprehension

Imagine you have a JSON object that has some null values, which you need to remove:

import json
json_data = '{"customer_id": 12345, "name": "Jordan", "email": null, "phone": "555-1234", "address": null}'
data_dict = json.loads(json_data)

Output:

{'customer_id': 12345, 'name': 'Jordan', 'email': None, 'phone': '555-1234', 'address': None}

Here, we convert the JSON string to a dictionary, where None represents null values.

Next, use dictionary comprehension to remove null values:

cleaned_data = {k: v for k, v in data_dict.items() if v is not None}
print(cleaned_data)

Output:

{'customer_id': 12345, 'name': 'Jordan', 'phone': '555-1234'}

In this step, the comprehension iterates over each key-value pair in the dictionary, including them only if the value is not None.

 

Iteration and Deletion

Assume you have the same initial JSON object:

data_dict = {'customer_id': 12345, 'name': 'Jordan', 'email': None, 'phone': '555-1234', 'address': None}

To remove null values by iterating and deleting, you can do the following:

for key in list(data_dict.keys()):
    if data_dict[key] is None:
        del data_dict[key]
print(data_dict)

Output:

{'customer_id': 12345, 'name': 'Jordan', 'phone': '555-1234'}

In this code, we create a list of the dictionary’s keys and iterate over it. If a value associated with a key is None, we delete that key-value pair.

Using list(data_dict.keys()) is important to avoid a runtime error that occurs when the size of the dictionary changes during iteration.

 

Remove Null from Nested JSON

Let’s consider a more complex JSON structure with nested elements:

nested_json_data = {
    "customer_id": 12345,
    "name": "Jordan",
    "contact_info": {
        "email": None,
        "phone": "555-1234",
        "social_media": {
            "facebook": None,
            "twitter": "@jordan123"
        }
    },
    "addresses": [None, {"street": "123 Elm St", "city": "Springfield"}]
}

To remove null values from this nested structure, you’ll need a function that can recursively handle dictionaries and lists:

def remove_nulls(value):
    if isinstance(value, dict):
        return {k: remove_nulls(v) for k, v in value.items() if v is not None}
    elif isinstance(value, list):
        return [remove_nulls(item) for item in value if item is not None]
    else:
        return value
cleaned_data = remove_nulls(nested_json_data)
print(cleaned_data)

Output:

{
    'customer_id': 12345,
    'name': 'Jordan',
    'contact_info': {
        'phone': '555-1234',
        'social_media': {'twitter': '@jordan123'}
    },
    'addresses': [{'street': '123 Elm St', 'city': 'Springfield'}]
}

In this function, remove_nulls, we check if the input is a dictionary or a list.

If it’s a dictionary, we use dictionary comprehension to remove null values, and if it’s a list, we use a list comprehension.