Ostatnia ankieta <abbr title="coroczna ankieta przeprowadza w środowisku programistów języka Python">Python developer survey</abbr> jasno wskazuje, że <a href="https://www.jetbrains.com/research/python-developers-survey-2017/#tools-and-features" class="external-link" target="_blank">najczęściej używaną funkcjonalnością jest autouzupełnianie w edytorze</a>.

It uses Marshmallow underneath to do the data validation. And it was created by the same developers.

It's a great tool and I have used it a lot too, before having **FastAPI**.

!!! info
    Webargs was created by the same Marshmallow developers.

!!! check "Inspired **FastAPI** to"
    Have automatic validation of incoming request data.

</div>

With this feature from **Pydantic v2**, your API documentation is more **precise**, and if you have autogenerated clients and SDKs, they will be more precise too, with a better **developer experience** and consistency. 🎉

## Do not Separate Schemas

Now, there are some cases where you might want to have the **same schema for input and output**.

J'ai testé plusieurs idées dans les éditeurs Python les plus populaires : PyCharm, VS Code, les éditeurs basés sur Jedi.

D'après la dernière <a href="https://www.jetbrains.com/research/python-developers-survey-2018/#development-tools" class="external-link" target="_blank">Enquête Développeurs Python</a>, cela couvre environ 80% des utilisateurs.

**FastAPI** has a very powerful but intuitive **<abbr title="also known as components, resources, providers, services, injectables">Dependency Injection</abbr>** system.

It is designed to be very simple to use, and to make it very easy for any developer to integrate other components with **FastAPI**.

## What is "Dependency Injection"

Trong lần khảo sát cuối cùng dành cho các lập trình viên Python, đã rõ ràng <a href="https://www.jetbrains.com/research/python-developers-survey-2017/#tools-and-features" class="external-link" target="_blank">rằng đa số các lập trình viên sử dụng tính năng "autocompletion"</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.

                    corresponding JSON. But if the data in the object returned is not
                    valid, that would mean a violation of the contract with the client,
                    so it's an error from the API developer. So, FastAPI will raise an
                    error and return a 500 error code (Internal Server Error).

                Read more about it in the

!!! note "Technical Details"
    You could also use `from starlette.responses import HTMLResponse`.

    **FastAPI** provides the same `starlette.responses` as `fastapi.responses` just as a convenience for you, the developer. But most of the available responses come directly from Starlette.

### `Response`

The main `Response` class, all the other responses inherit from it.

You can return it directly.

```JSON
{
  "username": "johndoe",
  "email": "******@****.***",
  "full_name": "John Doe",
  "disabled": false
}
```

<img src="/img/tutorial/security/image09.png">

Wenn Sie die Developer Tools öffnen, können Sie sehen, dass die gesendeten Daten nur den Token enthalten. Das Passwort wird nur bei der ersten Anfrage gesendet, um den Benutzer zu authentisieren und diesen Zugriffstoken zu erhalten, aber nicht mehr danach: