Without a data validation system, you would have to do all the checks by hand, in code.

These features are what Marshmallow was built to provide. It is a great library, and I have used it a lot before.

        "/items/plumbus?token=jessica", headers={"X-Token": "fake-super-secret-token"}
    )
    assert response.status_code == 200, response.text
    assert response.json() == {"item_id": "plumbus", "name": "The great Plumbus"}


def test_put_forbidden(client: TestClient):
    response = client.put(
        "/items/bar?token=jessica", headers={"X-Token": "fake-super-secret-token"}
    )

        "/items/plumbus?token=jessica", headers={"X-Token": "fake-super-secret-token"}
    )
    assert response.status_code == 200, response.text
    assert response.json() == {"item_id": "plumbus", "name": "The great Plumbus"}


@needs_py39
def test_put_forbidden(client: TestClient):
    response = client.put(
        "/items/bar?token=jessica", headers={"X-Token": "fake-super-secret-token"}
    )

So, the thief won't be able to try to use that password in another system (as many users use the same password everywhere, this would be dangerous).

## Install `passlib`

PassLib is a great Python package to handle password hashes.

It supports many secure hashing algorithms and utilities to work with them.

The recommended algorithm is "Bcrypt".

So, install PassLib with Bcrypt:

<div class="termy">

        "/items/plumbus?token=jessica", headers={"X-Token": "fake-super-secret-token"}
    )
    assert response.status_code == 200, response.text
    assert response.json() == {"item_id": "plumbus", "name": "The great Plumbus"}


def test_put_forbidden(client: TestClient):
    response = client.put(
        "/items/bar?token=jessica", headers={"X-Token": "fake-super-secret-token"}
    )

That means that any value read in Python from an environment variable will be a `str`, and any conversion to a different type or validation has to be done in code.

## Pydantic `Settings`

Fortunately, Pydantic provides a great utility to handle these settings coming from environment variables with <a href="https://docs.pydantic.dev/latest/usage/pydantic_settings/" class="external-link" target="_blank">Pydantic: Settings management</a>.

* **Fast to code**: Increase the speed to develop features by about 200% to 300%. *
* **Fewer bugs**: Reduce about 40% of human (developer) induced errors. *
* **Intuitive**: Great editor support. <abbr title="also known as auto-complete, autocompletion, IntelliSense">Completion</abbr> everywhere. Less time debugging.
* **Easy**: Designed to be easy to use and learn. Less time reading docs.

* **Fast to code**: Increase the speed to develop features by about 200% to 300%. *
* **Fewer bugs**: Reduce about 40% of human (developer) induced errors. *
* **Intuitive**: Great editor support. <abbr title="also known as auto-complete, autocompletion, IntelliSense">Completion</abbr> everywhere. Less time debugging.
* **Easy**: Designed to be easy to use and learn. Less time reading docs.