* one or more methods to modify the behavior of the backing multiset as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingMultiset} forward <b>indiscriminately</b> to
 * the methods of the delegate. For example, overriding {@link #add(Object, int)} alone <b>will

 * should override one or more methods to modify the behavior of the backing multiset as desired per
 * the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingSortedMultiset} forward
 * <b>indiscriminately</b> to the methods of the delegate. For example, overriding {@link

& 👥 💪 🚮 📇 `dependencies` 👈 🔜 🚮 🌐 *➡ 🛠️* 📻 & 🔜 🛠️/❎ 🔠 📨 ⚒ 👫.

/// tip

🗒 👈, 🌅 💖 [🔗 *➡ 🛠️ 👨‍🎨*](dependencies/dependencies-in-path-operation-decorators.md){.internal-link target=_blank}, 🙅‍♂ 💲 🔜 🚶‍♀️ 👆 *➡ 🛠️ 🔢*.

///

🔚 🏁 👈 🏬 ➡ 🔜:

* `/items/`
* `/items/{item_id}`

...👥 🎯.

* 👫 🔜 ™ ⏮️ 📇 🔖 👈 🔌 👁 🎻 `"items"`.

That's it.

**2 lines**.

And it has the same shape and structure that all your *path operation functions* have.

You can think of it as a *path operation function* without the "decorator" (without the `@app.get("/some-path")`).

And it can return anything you want.

In this case, this dependency expects:

* An optional query parameter `q` that is a `str`.

 * override one or more methods to modify the behavior of the backing set as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingNavigableSet} forward <i>indiscriminately</i>
 * to the methods of the delegate. For example, overriding {@link #add} alone <i>will not</i> change

 * override one or more methods to modify the behavior of the backing set as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingNavigableSet} forward <i>indiscriminately</i>
 * to the methods of the delegate. For example, overriding {@link #add} alone <i>will not</i> change

      - tutorial/dependencies/index.md
      - tutorial/dependencies/classes-as-dependencies.md
      - tutorial/dependencies/sub-dependencies.md
      - tutorial/dependencies/dependencies-in-path-operation-decorators.md
      - tutorial/dependencies/global-dependencies.md
      - tutorial/dependencies/dependencies-with-yield.md
    - Security:
      - tutorial/security/index.md
      - tutorial/security/first-steps.md

{* ../../docs_src/first_steps/tutorial001.py hl[6] *}

`@app.get("/")` 💬 **FastAPI** 👈 🔢 ▶️️ 🔛 🈚 🚚 📨 👈 🚶:

* ➡ `/`
* ⚙️ <abbr title="an HTTP GET method"><code>get</code> 🛠️</abbr>

/// info | `@decorator` ℹ

👈 `@something` ❕ 🐍 🤙 "👨‍🎨".

👆 🚮 ⚫️ 🔛 🔝 🔢. 💖 📶 📔 👒 (👤 💭 👈 🌐❔ ⚖ 👟 ⚪️➡️).

 "👨‍🎨" ✊ 🔢 🔛 &amp; 🔨 🕳 ⏮️ ⚫️.

👆 💼, 👉 👨‍🎨 💬 **FastAPI** 👈 🔢 🔛 🔗 **➡** `/` ⏮️ **🛠️** `get`.

/**
 * A map which forwards all its method calls to another map. Subclasses should override one or more
 * methods to modify the behavior of the backing map as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingMap} forward <i>indiscriminately</i> to the
 * methods of the delegate. For example, overriding {@link #put} alone <i>will not</i> change the

* **Renouvelable**:
    * Pydantic permet de définir de nouveaux types de données ou vous pouvez étendre la validation avec des méthodes sur un modèle décoré avec le<abbr title="en anglais: validator decorator"> décorateur de validation</abbr>