And dependencies can be created in a very simple and intuitive way that allows you to just import the Python packages you need, and integrate them with your API functions in a couple of lines of code, *literally*.

You will see examples of this in the next chapters, about relational and NoSQL databases, security, etc.

* Also don't worry about style rules, there are already automatized tools checking that.

And if there's any other style or consistency need, I'll ask directly for that, or I'll add commits on top with the needed changes.

### Check the code

* Check and read the code, see if it makes sense, **run it locally** and see if it actually solves the problem.

But whenever you need them and go and learn them, know that you can already use them directly in **FastAPI**.

### Pydantic v1 `regex` instead of `pattern`

Before Pydantic version 2 and before FastAPI 0.100.0, the parameter was called `regex` instead of `pattern`, but it's now deprecated.

You could still see some code using it:

!!! note "`async` Technical Details"
    When you use the `async` methods, **FastAPI** runs the file methods in a threadpool and awaits for them.

!!! note "Starlette Technical Details"
    **FastAPI**'s `UploadFile` inherits directly from **Starlette**'s `UploadFile`, but adds some necessary parts to make it compatible with **Pydantic** and the other parts of FastAPI.

## What is "Form Data"

import pytest
from dirty_equals import IsDict
from fastapi import FastAPI
from fastapi.testclient import TestClient


@pytest.fixture(name="app")
def get_app():
    from docs_src.request_forms_and_files.tutorial001 import app

    return app


@pytest.fixture(name="client")
def get_client(app: FastAPI):
    client = TestClient(app)
    return client


def test_post_form_no_body(client: TestClient):

Dans le dernier sondage effectué auprès de développeurs python il était clair que <a href="https://www.jetbrains.com/research/python-developers-survey-2017/#tools-and-features" class="external-link" target="_blank">la fonctionnalité la plus utilisée est "l’autocomplétion"</a>.

Tout le framework **FastAPI** a été conçu avec cela en tête. L'autocomplétion fonctionne partout.

!!! tip "Tipp"
    Sie können <a href="https://help.github.com/en/github/collaborating-with-issues-and-pull-requests/commenting-on-a-pull-request" class="external-link" target="_blank">Kommentare mit Änderungsvorschlägen</a> zu vorhandenen Pull Requests hinzufügen.

participant operation as Path Operation
participant tasks as Background tasks

    Note over client,tasks: Can raise exception for dependency, handled after response is sent
    Note over client,operation: Can raise HTTPException and can change the response
    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise
        dep -->> handler: Raise HTTPException
        handler -->> client: HTTP error response

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}
```

!!! note "Detalhes Técnicos"
    Você também pode usar `from starlette.requests import Request` and `from starlette.responses import JSONResponse`.

Na última pesquisa do desenvolvedor Python ficou claro <a href="https://www.jetbrains.com/research/python-developers-survey-2017/#tools-and-features" class="external-link" target="_blank">que o recurso mais utilizado é o "auto completar"</a>.

Todo o _framework_ **FastAPI** é feito para satisfazer isso. Auto completação funciona em todos os lugares.