# Exceptions - `HTTPException` and `WebSocketException`

These are the exceptions that you can raise to show errors to the client.

When you raise an exception, as would happen with normal Python, the rest of the execution is aborted. This way you can raise these exceptions from anywhere in the code to abort a request and show the error to the client.

You can use:

* `HTTPException`
* `WebSocketException`

```Python hl_lines="2-3  23"
{!../../docs_src/wsgi/tutorial001.py!}
```

## Check it

Now, every request under the path `/v1/` will be handled by the Flask application.

And the rest will be handled by **FastAPI**.

If you run it and go to <a href="http://localhost:8000/v1/" class="external-link" target="_blank">http://localhost:8000/v1/</a> you will see the response from Flask:

```txt

          script: |
            const output = `
            Some bad merge is found:
            \`\`\`
            ${{ env.OUTPUT }}
            \`\`\`
            `;
            github.rest.issues.createComment({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: output

* <a href="https://alternativeto.net/software/fastapi/" class="external-link" target="_blank">Votez pour **FastAPI** sur AlternativeTo</a>.
* <a href="https://github.com/marmelab/awesome-rest/pull/93" class="external-link" target="_blank">Votez pour **FastAPI** sur awesome-rest</a>.

## Aider les autres à résoudre les problèmes dans GitHub

                  @Override
                  protected List<String> create(String[] elements) {
                    String[] rest = new String[elements.length - 1];
                    arraycopy(elements, 1, rest, 0, elements.length - 1);
                    return Lists.asList(elements[0], rest);
                  }
                })
            .named("Lists.asList, 2 parameter")
            .withFeatures(

                  @Override
                  protected List<String> create(String[] elements) {
                    String[] rest = new String[elements.length - 1];
                    arraycopy(elements, 1, rest, 0, elements.length - 1);
                    return Lists.asList(elements[0], rest);
                  }
                })
            .named("Lists.asList, 2 parameter")
            .withFeatures(

### <a href="https://www.django-rest-framework.org/" class="external-link" target="_blank">Django REST Framework</a>

Django REST framework a été conçu comme une boîte à outils flexible permettant de construire des API Web à partir de Django, afin d'améliorer ses capacités en matière d'API.

 *   <li>{@link MoreObjects}
 *   <li>{@link Preconditions}
 *   <li>{@link StandardSystemProperty}
 *   <li>{@link Stopwatch}
 *   <li>{@link Throwables}
 *   <li>{@link Verify}
 * </ul>
 *
 * <h3>The rest</h3>
 *
 * This package also contains some classes with niche use cases (e.g., {@link Utf8} and {@link
 * Defaults}), as well as a number of classes that have been superseded by additions to the JDK.
 */
@CheckReturnValue

* how many of our REST services do not map directory to a method in the application interface?

- an example of adding js

```

</div>

////

Omdat omgevingsvariabelen buiten de code kunnen worden ingesteld, maar wel door de code kunnen worden gelezen en niet hoeven te worden opgeslagen (gecommit naar `git`) met de rest van de bestanden, worden ze vaak gebruikt voor configuraties of **instellingen**.