# 🔗 ⏮️ 🌾

FastAPI 🐕‍🦺 🔗 👈 <abbr title='sometimes also called "exit", "cleanup", "teardown", "close", "context managers", ...'>➕ 🔁 ⏮️ 🏁</abbr>.

👉, ⚙️ `yield` ↩️ `return`, &amp; ✍ ➕ 🔁 ⏮️.

/// tip

⚒ 💭 ⚙️ `yield` 1️⃣ 👁 🕰.

///

/// note | 📡 ℹ

🙆 🔢 👈 ☑ ⚙️ ⏮️:

* <a href="https://docs.python.org/3/library/contextlib.html#contextlib.contextmanager" class="external-link" target="_blank">`@contextlib.contextmanager`</a> ⚖️

Dieser Teil ist ziemlich normal, der größte Teil des Codes ist Ihnen wahrscheinlich bereits bekannt:

{* ../../docs_src/openapi_callbacks/tutorial001.py hl[9:13,36:53] *}

/// tip | Tipp

Der Query-Parameter `callback_url` verwendet einen Pydantic-<a href="https://docs.pydantic.dev/latest/api/networks/" class="external-link" target="_blank">Url</a>-Typ.

///

│   ├── main.py
│   ├── dependencies.py
│   └── routers
│   │   ├── __init__.py
│   │   ├── items.py
│   │   └── users.py
│   └── internal
│       ├── __init__.py
│       └── admin.py
```

/// tip

📤 📚 `__init__.py` 📁: 1️⃣ 🔠 📁 ⚖️ 📁.

👉 ⚫️❔ ✔ 🏭 📟 ⚪️➡️ 1️⃣ 📁 🔘 ➕1️⃣.

🖼, `app/main.py` 👆 💪 ✔️ ⏸ 💖:

```
from app.routers import items
```

///

```

</div>

## Em Detalhes

O marcador `@pytest.mark.anyio` informa ao pytest que esta função de teste deve ser invocada de maneira assíncrona:

{* ../../docs_src/async_tests/test_main.py hl[7] *}

/// tip | Dica

Note que a função de teste é `async def` agora, no lugar de apenas `def` como quando estávamos utilizando o `TestClient` anteriormente.

///

{* ../../docs_src/async_tests/test_main.py hl[7] *}

/// tip

🗒 👈 💯 🔢 🔜 `async def` ↩️ `def` ⏭ 🕐❔ ⚙️ `TestClient`.

///

⤴️ 👥 💪 ✍ `AsyncClient` ⏮️ 📱, & 📨 🔁 📨 ⚫️, ⚙️ `await`.

{* ../../docs_src/async_tests/test_main.py hl[9:12] *}

👉 🌓:

```Python
response = client.get('/')
```

...👈 👥 ⚙️ ⚒ 👆 📨 ⏮️ `TestClient`.

/// tip

🗒 👈 👥 ⚙️ 🔁/⌛ ⏮️ 🆕 `AsyncClient` - 📨 🔁.

///

            // More stuff here
    }
}
```

/// tip

👀 🚘-🏗 💽 ⏮️ `url` 💲 `/api/v1`, ✊ ⚪️➡️ `root_path`.

///

🩺 🎚 <a href="http://127.0.0.1:9999/api/v1/docs" class="external-link" target="_blank">http://127.0.0.1:9999/api/v1/docs</a> ⚫️ 🔜 👀 💖:

<img src="/img/tutorial/behind-a-proxy/image03.png">

/// tip

🩺 🎚 🔜 🔗 ⏮️ 💽 👈 👆 🖊.

///

---> 100%
```

</div>

## En Detalle

El marcador `@pytest.mark.anyio` le dice a pytest que esta función de test debe ser llamada asíncronamente:

{* ../../docs_src/async_tests/test_main.py hl[7] *}

/// tip | Consejo

Note que la función de test ahora es `async def` en lugar de solo `def` como antes al usar el `TestClient`.

///

& ⚫️ 🔜 ✔️ `access_token`, ⏮️ 🎻 ⚗ 👆 🔐 🤝.

👉 🙅 🖼, 👥 🔜 🍕 😟 & 📨 🎏 `username` 🤝.

/// tip

⏭ 📃, 👆 🔜 👀 🎰 🔐 🛠️, ⏮️ 🔐 #️⃣ &amp; <abbr title="JSON Web Tokens">🥙</abbr> 🤝.

✋️ 🔜, ➡️ 🎯 🔛 🎯 ℹ 👥 💪.

///

{* ../../docs_src/security/tutorial003.py hl[85] *}

/// tip

🔌, 👆 🔜 📨 🎻 ⏮️ `access_token` &amp; `token_type`, 🎏 👉 🖼.

```console
$ uv venv
```

</div>

/// tip

預設情況下，`uv` 會在一個名為 `.venv` 的目錄中建立一個虛擬環境。

但你可以透過傳遞一個額外的引數來自訂它，指定目錄的名稱。

///

////

這個命令會在一個名為 `.venv` 的目錄中建立一個新的虛擬環境。

/// details | `.venv`，或是其他名稱

你可以在不同的目錄下建立虛擬環境，但通常我們會把它命名為 `.venv`。

///

## 啟動虛擬環境

啟動新的虛擬環境來確保你運行的任何 Python 指令或安裝的套件都能使用到它。

/// tip

**每次**開始一個**新的終端會話**來在這個專案工作時，你都需要執行這個操作。

```

////

//// tab | Python 3.8+ non-Annotated

/// tip

Prefer to use the `Annotated` version if possible.

///

```Python hl_lines="1  4-6" title="app/dependencies.py"
{!> ../../docs_src/bigger_applications/app/dependencies.py!}
```

////

/// tip

We are using an invented header to simplify this example.