```

## カスタム例外ハンドラのインストール

カスタム例外ハンドラは<a href="https://www.starlette.io/exceptions/" class="external-link" target="_blank">Starletteと同じ例外ユーティリティ</a>を使用して追加することができます。

あなた（または使用しているライブラリ）が`raise`するかもしれないカスタム例外`UnicornException`があるとしましょう。

そして、この例外をFastAPIでグローバルに処理したいと思います。

カスタム例外ハンドラを`@app.exception_handler()`で追加することができます:

```Python hl_lines="5 6 7  13 14 15 16 17 18  24"

import binascii
from base64 import b64decode
from typing import Optional

from fastapi.exceptions import HTTPException
from fastapi.openapi.models import HTTPBase as HTTPBaseModel
from fastapi.openapi.models import HTTPBearer as HTTPBearerModel
from fastapi.security.base import SecurityBase
from fastapi.security.utils import get_authorization_scheme_param
from pydantic import BaseModel
from starlette.requests import Request

                    "type": "type_error.dict",
                }
            ]
        }
    )


@needs_py310
def test_other_exceptions(client: TestClient):
    with patch("json.loads", side_effect=Exception):
        response = client.post("/items/", json={"test": "test2"})
        assert response.status_code == 400, response.text


@needs_py310

                    "type": "type_error.dict",
                }
            ]
        }
    )


def test_other_exceptions(client: TestClient):
    with patch("json.loads", side_effect=Exception):
        response = client.post("/items/", json={"test": "test2"})
        assert response.status_code == 400, response.text


def test_openapi_schema(client: TestClient):

    ```

An alternative you could use to catch exceptions (and possibly also raise another `HTTPException`) is to create a [Custom Exception Handler](../handling-errors.md#install-custom-exception-handlers){.internal-link target=_blank}.

## Dependencies with `yield` and `except`

    opt Löst aus
        operation -->> dep: Löst Exception aus (z. B. HTTPException)
        opt Handhabt
            dep -->> dep: Kann Exception abfangen, eine neue HTTPException auslösen, andere Exceptions auslösen
            dep -->> handler: Leitet Exception automatisch weiter
        end
        handler -->> client: HTTP-Error-Response
    end
    operation ->> client: Sendet Response an Client

from typing import Any, Dict, List, Optional, Union, cast

from fastapi.exceptions import HTTPException
from fastapi.openapi.models import OAuth2 as OAuth2Model
from fastapi.openapi.models import OAuthFlows as OAuthFlowsModel
from fastapi.param_functions import Form
from fastapi.security.base import SecurityBase
from fastapi.security.utils import get_authorization_scheme_param
from starlette.requests import Request

Nehmen wir an, Sie haben eine benutzerdefinierte Exception `UnicornException`, die Sie (oder eine Bibliothek, die Sie verwenden) `raise`n könnten.

Und Sie möchten diese Exception global mit FastAPI handhaben.

▶️ ✍ 👑 📃, `docs/ht/index.md`.

⤴️ 👆 💪 😣 ⏮️ ⏮️ 👩‍🌾, "♻ 🇪🇸".

##### 🆕 🇪🇸 🚫 🐕‍🦺

🚥 🕐❔ 🏃‍♂ 🖖 💽 ✍ 👆 🤚 ❌ 🔃 🇪🇸 🚫 ➖ 🐕‍🦺, 🕳 💖:

```
 raise TemplateNotFound(template)
jinja2.exceptions.TemplateNotFound: partials/language/xx.html
```

👈 ⛓ 👈 🎢 🚫 🐕‍🦺 👈 🇪🇸 (👉 💼, ⏮️ ❌ 2️⃣-🔤 📟 `xx`).

✋️ 🚫 😟, 👆 💪 ⚒ 🎢 🇪🇸 🇪🇸 & ⤴️ 💬 🎚 🩺.

    "bg": "not set",
    "sync_bg": "not set",
}

errors = []


async def get_state():
    return state


class AsyncDependencyError(Exception):
    pass


class SyncDependencyError(Exception):
    pass


class OtherDependencyError(Exception):
    pass


async def asyncgen_state(state: Dict[str, str] = Depends(get_state)):
    state["/async"] = "asyncgen started"
    yield state["/async"]