Why Returning None Is Bad and Better Ways to Handle Missing Values in Python

Previously I used to return None for missing values, but that can cause unexpected errors and make debugging difficult.

<code>user_data = {"name": "Kiran", "age": 25}

def get_email(user):
    return user.get("email")

e = get_email(user_data)
print(e.upper())
</code>

The program crashes because e is None ; we need to add a check like if e is not None .

1. Try using default values

If a value is missing, return a default.

Don’t do this:

<code>def get_username(user):
    if 'name' in user:
        return user['name']
    return None
</code>

Instead, do this:

<code>def get_username(user):
    return user.get('name', "Guest")
</code>

This returns a default value ("Guest") so the program won’t crash; use defaults only when they make sense, otherwise raise an exception.

5. Use result pattern

For functions that may fail, return a structured result instead of None .

<code>from typing import NamedTuple, Union

class Result(NamedTuple):
    success: bool
    value: Union[str, None]

def get_country(user) -> Result:
    if 'country' in user:
        return Result(True, user['country'])
    return Result(False, None)

result = get_country({})
if not result.success:
    print("Country not found!")
</code>

This pattern makes it explicit whether the function succeeded.