{* ../../docs_src/path_params/tutorial001.py hl[6:7] *}

La valeur du paramètre `item_id` sera transmise à la fonction dans l'argument `item_id`.

Donc, si vous exécutez cet exemple et allez sur <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>,
vous verrez comme réponse :

/// tip

This section is useful only to a handful of people, team members with permissions to manage the repository. You can probably skip it. 😉

///

...so, you are a [team member of FastAPI](./fastapi-people.md#team){.internal-link target=_blank}? Wow, you are so cool! 😎

### Install `pydantic-settings` { #install-pydantic-settings }

First, make sure you create your [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then install the `pydantic-settings` package:

<div class="termy">

```console

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

pode ser utilizada como uma dependência do **FastAPI**.

Например:

* <a href="https://code.visualstudio.com/docs/python/environments#_select-and-activate-an-environment" class="external-link" target="_blank">VS Code</a>
* <a href="https://www.jetbrains.com/help/pycharm/creating-virtual-environment.html" class="external-link" target="_blank">PyCharm</a>

/// tip | Подсказка

Обычно это делается один раз, при создании виртуальной среды разработки.

///

## 🔬 🌐 ⏮️ Traefik

👆 💪 💪 🏃 🥼 🌐 ⏮️ 🎞 ➡ 🔡 ⚙️ <a href="https://docs.traefik.io/" class="external-link" target="_blank">Traefik</a>.

<a href="https://github.com/containous/traefik/releases" class="external-link" target="_blank">⏬ Traefik</a>, ⚫️ 👁 💱, 👆 💪 ⚗ 🗜 📁 &amp; 🏃 ⚫️ 🔗 ⚪️➡️ 📶.

⤴️ ✍ 📁 `traefik.toml` ⏮️:

```TOML hl_lines="3"
[entryPoints]
  [entryPoints.http]

headers se pueden añadir <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">usando el prefijo 'X-'</a>.

Pero si tienes custom headers que deseas que un cliente en un navegador pueda ver, necesitas añadirlos a tus configuraciones de CORS ([CORS (Cross-Origin Resource Sharing)](cors.md){.internal-link target=_blank}) usando el parámetro `expose_headers` documentado en <a href="https://www.starlette.io/middleware/#corsmiddleware" class="external-link"...

    <div class="md-copyright__highlight">
        The FastAPI trademark is owned by <a href="https://tiangolo.com" target="_blank">@tiangolo</a> and is registered in the US and across other regions
    </div>
    {% if not config.extra.generator == false %}
    Made with
    <a href="https://squidfunk.github.io/mkdocs-material/" target="_blank" rel="noopener">
        Material for MkDocs
    </a>
    {% endif %}

    content: attr(data-ty-cursor);
    font-family: monospace;
    margin-left: 0.5em;
    -webkit-animation: blink 1s infinite;
            animation: blink 1s infinite;
}


/* Cursor animation */

@-webkit-keyframes blink {
    50% {
        opacity: 0;
    }
}

@keyframes blink {
    50% {
        opacity: 0;
    }

# Geçmişi, Tasarımı ve Geleceği

Bir süre önce, <a href="https://github.com/fastapi/fastapi/issues/3#issuecomment-454956920" class="external-link" target="_blank">bir **FastAPI** kullanıcısı sordu</a>:

> Bu projenin geçmişi nedir? Birkaç hafta içinde hiçbir yerden harika bir şeye dönüşmüş gibi görünüyor [...]

İşte o geçmişin bir kısmı.

## Alternatifler