* `read(size)`：按指定数量的字节或字符（`size` (`int`)）读取文件内容；
* `seek(offset)`：移动至文件 `offset` （`int`）字节处的位置；
    * 例如，`await myfile.seek(0) ` 移动到文件开头；
    * 执行 `await myfile.read()` 后，需再次读取已读取内容时，这种方法特别好用；
* `close()`：关闭文件。

因为上述方法都是 `async` 方法，要搭配「await」使用。

例如，在 `async` *路径操作函数* 内，要用以下方式读取文件内容：

```Python
contents = await myfile.read()
```

在普通 `def` *路径操作函数*  内，则可以直接访问 `UploadFile.file`，例如：

```Python

async def custom_http_exception_handler(request, exc):
    print(f"OMG! An HTTP error!: {repr(exc)}")
    return await http_exception_handler(request, exc)


@app.exception_handler(RequestValidationError)
async def validation_exception_handler(request, exc):
    print(f"OMG! The client sent invalid data!: {exc}")
    return await request_validation_exception_handler(request, exc)


@app.get("/items/{item_id}")

			}

			now := time.Now()
			if now.Sub(u.Queued) < time.Second {
				// let recently failed networks to reconnect
				// making MRF wait for 1s before retrying,
				// i.e 4 reconnect attempts.
				time.Sleep(time.Second)
			}

			// wait on timer per heal
			wait := healSleeper.Timer(context.Background())

			scan := madmin.HealNormalScan
			if u.BitrotScan {
				scan = madmin.HealDeepScan
			}

import * as fs from 'fs'

async function modifyOpenAPIFile(filePath) {
  try {
    const data = await fs.promises.readFile(filePath)
    const openapiContent = JSON.parse(data)

    const paths = openapiContent.paths
    for (const pathKey of Object.keys(paths)) {
      const pathData = paths[pathKey]
      for (const method of Object.keys(pathData)) {
        const operation = pathData[method]
        if (operation.tags && operation.tags.length > 0) {

   * @param timeoutDuration with timeoutUnit, the maximum length of time that callers are willing to
   *     wait on each method call to the proxy
   * @param timeoutUnit with timeoutDuration, the maximum length of time that callers are willing to
   *     wait on each method call to the proxy
   * @return a time-limiting proxy
   * @throws IllegalArgumentException if {@code interfaceType} is a regular class, enum, or

 * Object x = new MyClass() {
 *   ...
 *   protected void finalize() { latch.countDown(); ... }
 * };
 * x = null;  // Hint to the JIT that x is stack-unreachable
 * GcFinalization.await(latch);
 * }</pre>
 *
 * <p>Here's an example that uses a user-defined finalization predicate:
 *
 * <pre>{@code
 * final WeakHashMap<Object, Object> map = new WeakHashMap<>();
 * map.put(new Object(), Boolean.TRUE);

   * is complete. It does so by using daemon threads and adding a shutdown hook to wait for their
   * completion.
   *
   * <p>This is mainly for fixed thread pools. See {@link Executors#newFixedThreadPool(int)}.
   *
   * @param executor the executor to modify to make sure it exits when the application is finished
   * @param terminationTimeout how long to wait for the executor to finish before terminating the
   *     JVM

Dann können wir einen `AsyncClient` mit der App erstellen und mit `await` asynchrone Requests an ihn senden.

{* ../../docs_src/async_tests/test_main.py hl[9:12] *}

Das ist das Äquivalent zu:

```Python
response = client.get('/')
```

... welches wir verwendet haben, um unsere Requests mit dem `TestClient` zu machen.

/// tip | "Tipp"

Beachten Sie, dass wir async/await mit dem neuen `AsyncClient` verwenden – der Request ist asynchron.

///

Then we can create an `AsyncClient` with the app, and send async requests to it, using `await`.

{* ../../docs_src/async_tests/test_main.py hl[9:12] *}

This is the equivalent to:

```Python
response = client.get('/')
```

...that we used to make our requests with the `TestClient`.

/// tip

Note that we're using async/await with the new `AsyncClient` - the request is asynchronous.

///

/// warning

@app.websocket("/items/{item_id}")
async def websocket_item(item_id: str, websocket: WebSocket):
    route: APIWebSocketRoute = websocket.scope["route"]
    await websocket.accept()
    await websocket.send_json({"item_id": item_id, "path": route.path})


client = TestClient(app)


def test_get():
    response = client.get("/users/rick")