var_name: (String) string for name of environment variable, e.g. "TF_MYVAR".
    var_default: (String) default value string.
    ask_for_var: (String) string for how to ask for user input.
    check_success: (Function) function that takes one argument and returns a
      boolean. Should return True if the value provided is considered valid. May
      contain a complex error message if error_msg does not provide enough

		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrUnsupportedNotification: {
		Code:           "UnsupportedNotification",
		Description:    "MinIO server does not support Topic or Cloud Function based notifications.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidCopyPartRange: {
		Code:           "InvalidArgument",

	if o.IsLatest {
		ts.NumObjects = 1
	}
	return ts
}

// ToObjectInfo converts a replication object info to a partial ObjectInfo
// do not rely on this function to give you correct ObjectInfo, this
// function is merely and optimization.
func (ri ReplicateObjectInfo) ToObjectInfo() ObjectInfo {
	return ObjectInfo{
		Name:                       ri.Name,
		Bucket:                     ri.Bucket,

				if baseDir != "" && nbaseDir != "" && nbaseDir != SlashSeparator {
					baseDir = nbaseDir
				}
				continue
			}
		}
		break
	}
	return err
}

// Wrapper function to os.Rename, which calls reliableMkdirAll
// and reliableRenameAll. This is to ensure that if there is a
// racy parent directory delete in between we can simply retry
// the operation.

`yield` を使う依存関係は、さまざまなユースケースに対応し、いくつかの問題を修正するために時間とともに進化してきました。ここでは変更点の概要を説明します。

### `yield` と `scope` を伴う依存関係 { #dependencies-with-yield-and-scope }

バージョン 0.121.0 で、`yield` を使う依存関係に対して `Depends(scope="function")` がサポートされました。

`Depends(scope="function")` を使うと、`yield` の後の終了コードは、クライアントへレスポンスが返される前、*path operation 関数* が終了した直後に実行されます。

そして、`Depends(scope="request")`（デフォルト）を使う場合、`yield` の後の終了コードはレスポンス送信後に実行されます。

  // a tensor with the result.
  AbstractTensorHandle* AggregateGradients(
      absl::Span<AbstractTensorHandle* const> gradient_tensors) const override;

  // Calls the passed-in backward function.
  // op_type is the op's name provided in RecordOperation.
  absl::Status CallBackwardFunction(
      const string& op_type, GradientFunction* gradient_function,
      const std::vector<int64_t>& unneeded_gradients,

		h.failedMessages.Add(1)
		return errors.New("log buffer full")
	}

	return nil
}

// Cancel - cancels the target.
// All queued messages are flushed and the function returns afterwards.
// All messages sent to the target after this function has been called will be dropped.
func (h *Target) Cancel() {
	h.status.Store(statusClosed)
	h.storeCtxCancel()

	// Wait for messages to be sent...
	h.wg.Wait()

   * called by the {@link #escape(String)} method when it discovers that escaping is required. It is
   * protected to allow subclasses to override the fastpath escaping function to inline their
   * escaping test. See {@link CharEscaperBuilder} for an example usage.
   *
   * @param s the literal string to be escaped
   * @param index the index to start escaping from

    expectArrayContentsAnyOrder(createSamplesArray(), array);
  }

  /**
   * {@link Collection#toArray(Object[])} says: "Note that {@code toArray(new Object[0])} is
   * identical in function to {@code toArray()}."
   *
   * <p>For maximum effect, the collection under test should be created from an element array of a
   * type other than {@code Object[]}.
   */
  public void testToArray_isPlainObjectArray() {

首先，匯入 `BackgroundTasks`，並在你的路徑操作函式中定義一個型別為 `BackgroundTasks` 的參數：

{* ../../docs_src/background_tasks/tutorial001_py310.py hl[1,13] *}

**FastAPI** 會為你建立 `BackgroundTasks` 物件，並以該參數傳入。

## 建立任務函式 { #create-a-task-function }

建立一個作為背景任務執行的函式。

它只是個可接收參數的一般函式。

它可以是 `async def`，也可以是一般的 `def`，**FastAPI** 都能正確處理。

在此例中，任務函式會寫入檔案（模擬寄送電子郵件）。

由於寫入操作未使用 `async` 與 `await`，因此以一般的 `def` 定義該函式：