///

## デバッガーでコードを実行

コードから直接Uvicornサーバーを実行しているため、デバッガーから直接Pythonプログラム (FastAPIアプリケーション) を呼び出せます。

---

例えば、Visual Studio Codeでは、次のことが可能です:

* 「デバッグ」パネルに移動。
* 「構成の追加...」
* 「Python」を選択。
* オプション「`Python: Current File (Integrated Terminal)`」を指定してデバッガーを実行。

すると、**FastAPI** コードでサーバーが起動され、ブレークポイントで停止したりするでしょう。

以下の様な画面になります:

<img src="/img/tutorial/debugging/image01.png">

from fastapi.testclient import TestClient

from docs_src.security.tutorial001 import app

client = TestClient(app)


def test_no_token():
    response = client.get("/items")
    assert response.status_code == 401, response.text
    assert response.json() == {"detail": "Not authenticated"}
    assert response.headers["WWW-Authenticate"] == "Bearer"


def test_token():

import pytest
from fastapi.exceptions import FastAPIError
from fastapi.testclient import TestClient

from ...utils import needs_py39


@pytest.fixture(name="client")
def get_client():
    from docs_src.dependencies.tutorial008c_an_py39 import app

    client = TestClient(app)
    return client


@needs_py39
def test_get_no_item(client: TestClient):
    response = client.get("/items/foo")

Wenn Sie beispielsweise den Requestbody lesen oder manipulieren möchten, bevor er von Ihrer Anwendung verarbeitet wird.

/// danger | "Gefahr"

Dies ist eine „fortgeschrittene“ Funktion.

Wenn Sie gerade erst mit **FastAPI** beginnen, möchten Sie diesen Abschnitt vielleicht überspringen.

///

## Anwendungsfälle

Einige Anwendungsfälle sind:

from dirty_equals import IsDict
from fastapi import Depends, FastAPI, Security
from fastapi.security import OAuth2, OAuth2PasswordRequestFormStrict
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()

reusable_oauth2 = OAuth2(
    flows={
        "password": {
            "tokenUrl": "token",
            "scopes": {"read:users": "Read the users", "write:users": "Create users"},
        }
    }
)

from typing import Optional

from dirty_equals import IsDict
from fastapi import Depends, FastAPI, Security
from fastapi.security import OAuth2, OAuth2PasswordRequestFormStrict
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()

reusable_oauth2 = OAuth2(
    flows={
        "password": {
            "tokenUrl": "token",
            "scopes": {"read:users": "Read the users", "write:users": "Create users"},

---

**Note** : vous pouvez mélanger `def` et `async def` dans vos *fonctions de chemin* autant que nécessaire, **FastAPI** saura faire ce qu'il faut avec.

Au final, peu importe le cas parmi ceux ci-dessus, **FastAPI** fonctionnera de manière asynchrone et sera extrêmement rapide.

Mais si vous suivez bien les instructions ci-dessus, alors **FastAPI** pourra effectuer quelques optimisations et ainsi améliorer les performances.

## Détails techniques

from decimal import Decimal
from typing import List

from dirty_equals import IsDict, IsOneOf
from fastapi import FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel, condecimal

app = FastAPI()


class Item(BaseModel):
    name: str
    age: condecimal(gt=Decimal(0.0))  # type: ignore


@app.post("/items/")
def save_item_no_body(item: List[Item]):
    return {"item": item}

from dataclasses import field  # (1)
from typing import List, Union

from fastapi import FastAPI
from pydantic.dataclasses import dataclass  # (2)


@dataclass
class Item:
    name: str
    description: Union[str, None] = None


@dataclass
class Author:
    name: str
    items: List[Item] = field(default_factory=list)  # (3)


app = FastAPI()

Porém ao utilizar `Security` no lugar de `Depends`, o **FastAPI** saberá que ele pode declarar escopos de segurança, utilizá-los internamente, e documentar a API com o OpenAPI.

Mas quando você importa `Query`, `Path`, `Depends`, `Security` entre outros de `fastapi`, eles são na verdade funções que retornam classes especiais.

///

## Utilize `SecurityScopes`