Let's say you have a custom exception `UnicornException` that you (or a library you use) might `raise`.

And you want to handle this exception globally with FastAPI.

You could add a custom exception handler with `@app.exception_handler()`:

{* ../../docs_src/handling_errors/tutorial003_py310.py hl[5:7,13:18,24] *}

his,r,!1),n!==t)return e.stopImmediatePropagation(),e.preventDefault(),t}else n&&(_.set(this,r,ce.event.trigger(n[0],n.slice(1),this)),e.stopPropagation(),e.isImmediatePropagationStopped=Ne)}})):void 0===_.get(e,r)&&ce.event.add(e,r,Ne)}ce.event={global:{},add:function(t,e,n,r,i){var o,a,s,u,l,c,f,p,d,h,g,v=_.get(t);if($(t)){n.handler&&(n=(o=n).handler,i=o.selector),i&&ce.find.matchesSelector(J,i),n.guid||(n.guid=ce.guid++),(u=v.events)||(u=v.events=Object.create(null)),(a=v.handle)||(a=v.handle...

				continue
			}

			// Return error if KMS is not initialized
			if GlobalKMS == nil {
				rpt.SetStatus(bucket, fileName, fmt.Errorf("%s", errorCodes[ErrKMSNotConfigured].Description))
				continue
			}
			kmsKey := encConfig.KeyID()
			if kmsKey != "" {
				_, err := GlobalKMS.GenerateKey(ctx, &kms.GenerateKeyRequest{
					Name:           kmsKey,

		return nil, nil, err
	}

	payloadSize := int64(len(b))
	br := bytes.NewReader(b)
	hr, err := hash.NewReader(ctx, br, payloadSize, "", "", payloadSize)
	if err != nil {
		return nil, nil, err
	}
	if GlobalKMS == nil {
		return NewPutObjReader(hr), &ObjectOptions{MaxParity: true}, nil
	}

	// Note: Local variables with names ek, oek, etc are named inline with
	// acronyms defined here -

   * the original error (which was not constructing ServiceManager correctly).
   */
  public void testPartiallyConstructedManager() {
    Logger logger = Logger.getLogger("global");
    logger.setLevel(Level.FINEST);
    TestLogHandler logHandler = new TestLogHandler();
    logger.addHandler(logHandler);
    NoOpService service = new NoOpService();
    service.startAsync();

				bucketsToBeUpdated.Add(bucket)
				continue
			}

			// No IPs seem to intersect, this means that bucket exists but has
			// different IP addresses perhaps from a different deployment.
			// bucket names are globally unique in federation at a given
			// path prefix, name collision is not allowed. We simply log
			// an error and continue.
			bucketsInConflict.Add(bucket)
		}
	}

### Импорт `FastAPI` { #import-fastapi }

Вы импортируете и создаёте класс `FastAPI` как обычно.

И мы даже можем объявить [глобальные зависимости](dependencies/global-dependencies.md), которые будут объединены с зависимостями для каждого `APIRouter`:

{* ../../docs_src/bigger_applications/app_an_py310/main.py hl[1,3,7] title["app/main.py"] *}

                                        <div class="alert alert-success">${msg}</div>
                                    </la:info>
                                    <la:errors property="_global"/>
                                </div>
                                <c:if test="${crudMode==2}">
                                    <div class="form-group row">

   * the original error (which was not constructing ServiceManager correctly).
   */
  public void testPartiallyConstructedManager() {
    Logger logger = Logger.getLogger("global");
    logger.setLevel(Level.FINEST);
    TestLogHandler logHandler = new TestLogHandler();
    logger.addHandler(logHandler);
    NoOpService service = new NoOpService();
    service.startAsync();

        public String toString() {
            return stringPart.toString() + digitPart.toString();
        }
    }

    /**
     * Represents a version list item. This class is used both for the global item list and for sub-lists (which start
     * with '-(number)' in the version specification).
     */
    private static class ListItem extends ArrayList<Item> implements Item {
        @Override