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`

These exceptions can be imported directly from `fastapi`:

```python

!!! note "Remarque"
    Les sections de ce chapitre ne sont **pas nécessairement "avancées"**.

    Et il est possible que pour votre cas d'utilisation, la solution se trouve dans l'un d'entre eux.

## Lisez d'abord le didacticiel

Vous pouvez utiliser la plupart des fonctionnalités de **FastAPI** grâce aux connaissances du [Tutoriel - Guide de l'utilisateur](../tutorial/index.md){.internal-link target=_blank}.

        "01234567890123456789012345678901234567890123456789"
    )
    cache.edit(key)!!.abort()
    // Contains all valid characters.
    key = "abcdefghijklmnopqrstuvwxyz_0123456789"
    cache.edit(key)!!.abort()
    // Contains dash.
    key = "-20384573948576"
    cache.edit(key)!!.abort()
  }

  @ParameterizedTest
  @ArgumentsSource(FileSystemParamProvider::class)

Par exemple, vous ne pouvez pas mettre un modèle Pydantic dans une `JSONResponse` sans d'abord le convertir en un `dict` avec tous les types de données (comme `datetime`, `UUID`, etc.) convertis en types compatibles avec JSON.

            super.close()
            editor.commit()
          }
        }
    }

    override fun abort() {
      synchronized(this@Cache) {
        if (done) return
        done = true
        writeAbortCount++
      }
      cacheOut.closeQuietly()
      try {
        editor.abort()
      } catch (_: IOException) {
      }
    }

    override fun body(): Sink = body
  }

	// uploadIds [0].
	// Create bucket before initiating NewMultipartUpload.
	err := obj.MakeBucket(context.Background(), bucketName, MakeBucketOptions{})
	if err != nil {
		// Failed to create newbucket, abort.
		t.Fatalf("%s : %s", instanceType, err.Error())
	}

	// Test cases for signature-V2.
	testCasesV2 := []struct {
		expectedStatus int
		accessKey      string
		secretKey      string
	}{

	}{
		// Test case - 1.
		// Abort existing upload ID.
		{
			bucket:             bucketName,
			object:             objectName,
			uploadID:           uploadIDs[0],
			accessKey:          credentials.AccessKey,
			secretKey:          credentials.SecretKey,
			expectedRespStatus: http.StatusNoContent,
		},
		// Test case - 2.
		// Abort non-existing upload ID.
		{

				bucket, humanize.Ordinal(er.setIndex+1))
		}

		disks, _, healing := er.getOnlineDisksWithHealingAndInfo(true)
		if len(disks) == healing {
			// All drives in this erasure set were reformatted for some reasons, abort healing and mark it as successful
			healingLogIf(ctx, errors.New("all drives are in healing state, aborting.."))
			return nil
		}

		disks = disks[:len(disks)-healing] // healing drives are always at the end of the list

                      description: Fault injection policy to apply on HTTP traffic
                        at the client side.
                      properties:
                        abort:
                          description: Abort Http request attempts and return error
                            codes back to downstream service, giving the impression
                            that the upstream service is faulty.

	fi.IsLatest = true

	// Success, return object info.
	return fi.ToObjectInfo(bucket, object, opts.Versioned || opts.VersionSuspended), nil
}

// AbortMultipartUpload - aborts an ongoing multipart operation
// signified by the input uploadID. This is an atomic operation
// doesn't require clients to initiate multiple such requests.
//