value_is_sequence,
)
from fastapi.background import BackgroundTasks
from fastapi.concurrency import (
    asynccontextmanager,
    contextmanager_in_threadpool,
)
from fastapi.dependencies.models import Dependant, SecurityRequirement
from fastapi.logger import logger
from fastapi.security.base import SecurityBase
from fastapi.security.oauth2 import OAuth2, SecurityScopes
from fastapi.security.open_id_connect_url import OpenIdConnect

No nosso exemplo de código acima, nós não usamos ele diretamente, mas nós passamos para o FastAPI para ele usá-lo.

O parâmetro `lifespan` da aplicação `FastAPI` usa um **Gerenciador de Contexto Assíncrono**, então nós podemos passar nosso novo gerenciador de contexto assíncrono do `lifespan` para ele.

```Python hl_lines="22"

# Body – Verschachtelte Modelle

Mit **FastAPI** können Sie (dank Pydantic) beliebig tief verschachtelte Modelle definieren, validieren und dokumentieren.

## Listen als Felder

Sie können ein Attribut als Kindtyp definieren, zum Beispiel eine Python-`list`e.

//// tab | Python 3.10+

```Python hl_lines="12"
{!> ../../docs_src/body_nested_models/tutorial001_py310.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="14"

In our code example above, we don't use it directly, but we pass it to FastAPI for it to use it.

The `lifespan` parameter of the `FastAPI` app takes an **async context manager**, so we can pass our new `lifespan` async context manager to it.

{* ../../docs_src/events/tutorial003.py hl[22] *}

## Alternative Events (deprecated)

/// tip

There is an official project generator with **FastAPI** and **PostgreSQL** including a frontend and more tools: <a href="https://github.com/fastapi/full-stack-fastapi-template" class="external-link" target="_blank">https://github.com/fastapi/full-stack-fastapi-template</a>

///

Bevorzugen Sie die `Annotated`-Version, falls möglich.

///

```Python hl_lines="10"
{!> ../../docs_src/dependencies/tutorial011.py!}
```

////

In diesem Fall ist dieses `__call__` das, was **FastAPI** verwendet, um nach zusätzlichen Parametern und Unterabhängigkeiten zu suchen, und das ist es auch, was später aufgerufen wird, um einen Wert an den Parameter in Ihrer *Pfadoperation-Funktion* zu übergeben.

from typing import Annotated

from fastapi import Depends, FastAPI, HTTPException, status
from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm
from pydantic import BaseModel

fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "******@****.***",
        "hashed_password": "fakehashedsecret",
        "disabled": False,
    },
    "alice": {

```

</div>

强烈建议你在本地编写或复制代码，对其进行编辑并运行。

在编辑器中使用 FastAPI 会真正地展现出它的优势：只需要编写很少的代码，所有的类型检查，代码补全等等。

---

## 安装 FastAPI

第一个步骤是安装 FastAPI。

为了使用本教程，你可能需要安装所有的可选依赖及对应功能：

<div class="termy">

```console
$ pip install "fastapi[all]"

---> 100%
```

</div>

......以上安装还包括了 `uvicorn`，你可以将其用作运行代码的服务器。

/// note

你也可以分开来安装。

Aqui tem um mini <a href="https://sqlmodel.tiangolo.com/tutorial/fastapi/" class="external-link" target="_blank">tutorial de como usar SQLModel com FastAPI</a>. ✨

from typing import Annotated

from fastapi import Depends, FastAPI, HTTPException

app = FastAPI()


class InternalError(Exception):
    pass


def get_username():
    try:
        yield "Rick"
    except InternalError:
        print("We don't swallow the internal error here, we raise again 😎")
        raise


@app.get("/items/{item_id}")
def get_item(item_id: str, username: Annotated[str, Depends(get_username)]):