public static boolean fileExists(final String path) {
        final File file = new File(LaServletContextUtil.getServletContext().getRealPath(path));
        return file.exists();
    }

    public static String url(final String input) {
        if (input == null) {
            final String msg = "The argument 'input' should not be null.";
            throw new IllegalArgumentException(msg);
        }

    * Champs String (`str`), définition de longueur minimum ou maximale.
    * Nombres (`int`, `float`) avec valeur minimale and maximale, etc.

* Validation pour des types plus exotiques, tel que:
    * URL.
    * Email.
    * UUID.
    * ...et autres.

Toutes les validations sont gérées par le bien établi et robuste **Pydantic**.

### Sécurité et authentification

<img src="/img/tutorial/generate-clients/image07.png">

As you see, the method names now have the tag and then the function name, now they don't include information from the URL path and the HTTP operation.

### Preprocess the OpenAPI Specification for the Client Generator

The generated code still has some **duplicated information**.

litigation is filed.

All Recipient's rights under this Agreement shall terminate if it
fails to comply with any of the material terms or conditions of this
Agreement and does not cure such failure in a reasonable period of
time after becoming aware of such noncompliance. If all Recipient's
rights under this Agreement terminate, Recipient agrees to cease use

🔜, 🏃 `uvicorn`, ⚙️ 🕹 `app.main` & 🔢 `app`:

<div class="termy">

```console
$ uvicorn app.main:app --reload

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

&amp; 📂 🩺 <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

👆 🔜 👀 🏧 🛠️ 🩺, ✅ ➡ ⚪️➡️ 🌐 🔁, ⚙️ ☑ ➡ (&amp; 🔡) &amp; ☑ 🔖:

<div class="termy">

```console
$ ADMIN_EMAIL="******@****.***" APP_NAME="ChimichangApp" uvicorn main:app

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

/// tip | "Tipp"

Um mehrere Umgebungsvariablen für einen einzelnen Befehl festzulegen, trennen Sie diese einfach durch ein Leerzeichen und fügen Sie alle vor dem Befehl ein.

Sau đó, bạn thử hỏi người bạn cũ của mình, autocompletion của trình soạn thảo.

Bạn gõ tham số đầu tiên của hàm, `first_name`, sau đó một dấu chấm (`.`) và sau đó ấn `Ctrl+Space` để kích hoạt bộ hoàn thành.

Nhưng đáng buồn, bạn không nhận được điều gì hữu ích cả:

<img src="/img/python-types/image01.png">

### Thêm kiểu dữ liệu

Hãy sửa một dòng từ phiên bản trước.

        if (auth != null) {
            int hash = (auth.getUsername() + auth.getPassword()).hashCode();
            buffer.append(hash).append('@');
        }

        // consider the URL (instead of the id) as this most closely relates to the contents in the repo
        buffer.append(repository.getUrl());

        return buffer.toString();
    }

  // Since non-resource URLs are not namespaced, this field is only applicable for ClusterRoles referenced from a ClusterRoleBinding.
  // Rules can either apply to API resources (such as "pods" or "secrets") or non-resource URL paths (such as "/api"),  but not both.
  // +optional
  repeated string nonResourceURLs = 5;
}

// Role is a namespaced, logical grouping of PolicyRules that can be referenced as a unit by a RoleBinding.

                        }
                        if (StringUtil.isBlank(favoriteUrl)) {
                            throw new WebApiException(HttpServletResponse.SC_BAD_REQUEST, "URL is null.");
                        }

                        boolean found = false;
                        for (final String id : docIds) {
                            if (docId.equals(id)) {