* đường dẫn `/`
* sử dụng một <abbr title="an HTTP GET method">toán tử<code>get</code></abbr>

/// info | Thông tin về "`@decorator`"

Cú pháp `@something` trong Python được gọi là một "decorator".

Bạn đặt nó trên một hàm. Giống như một chiếc mũ xinh xắn (Tôi ddonas đó là lí do mà thuật ngữ này ra đời).

Một "decorator" lấy một hàm bên dưới và thực hiện một vài thứ với nó.

# checks for cross-file issues like bad includes or missing BUILD definitions.
#
# We can't test on the windows toolchains because they're using a legacy
# toolchain format (or something) that specifies the toolchain directly instead
# of as a "repository". They can't be valid on Linux because Linux can't do
# anything with a Windows-only toolchain, and bazel errors if trying to build
# that directory.

///

### Pydantic- und FastAPI-`examples`

Wenn Sie `examples` innerhalb eines Pydantic-Modells hinzufügen, indem Sie `schema_extra` oder `Field(examples=["something"])` verwenden, wird dieses Beispiel dem **JSON-Schema** für dieses Pydantic-Modell hinzugefügt.

     * This property is a comma separated list of entries with the syntax <code>GAV&gt;GAV</code>.
     * The first <code>GAV</code> can contain <code>*</code> for any elem (so <code>*:*:*</code> would mean ALL, something
     * you don't want). The second <code>GAV</code> is either fully specified, or also can contain <code>*</code>,
     * then it behaves as "ordinary relocation": the coordinate is preserved from relocated artifact.

为此，你可以声明`None`是一个有效的类型，并仍然使用`default=...`：

```Python hl_lines="9"
{!../../docs_src/query_params_str_validations/tutorial006c.py!}
```

/// tip

Pydantic 是 FastAPI 中所有数据验证和序列化的核心，当你在没有设默认值的情况下使用 `Optional` 或 `Union[Something, None]` 时，它具有特殊行为，你可以在 Pydantic 文档中阅读有关<a href="https://docs.pydantic.dev/latest/concepts/models/#required-optional-fields" class="external-link" target="_blank">必需可选字段</a>的更多信息。

///

### 使用Pydantic中的`Required`代替省略号(`...`)

//
// TODO(allenl): There are some use-cases that are only supported by copying to
// host at the moment (e.g. debug print on a tensor, .numpy(), etc.). We either
// need to return something here or address these use-cases one by one.
TFE_TensorHandle* CopyTensorFromParallelDevice(TFE_Context* context,
                                               TFE_TensorHandle* tensor,

			}

		case <-time.After(ztunnelKeepAliveCheckInterval):
			// do a short read, just to see if the connection to ztunnel is
			// still alive. As ztunnel shouldn't send anything unless we send
			// something first, we expect to get an os.ErrDeadlineExceeded error
			// here if the connection is still alive.
			// note that unlike tcp connections, reading is a good enough test here.
			_, err := conn.readMessage(time.Second / 100)

        if (submittingTaskQueue.thread == submitting) {
          sequencer = null;
          // Submit from inside a reentrant submit. We don't know if this one will be reentrant (and
          // can't know without submitting something to the executor) so queue to run iteratively.
          // Task must be null, since each execution on this executor can only produce one more
          // execution.
          checkState(submittingTaskQueue.nextTask == null);

```Python hl_lines="7"
{!> ../../docs_src/query_params_str_validations/tutorial006c_py310.py!}
```

////

/// tip

Pydantic, ❔ ⚫️❔ 🏋️ 🌐 💽 🔬 &amp; 🛠️ FastAPI, ✔️ 🎁 🎭 🕐❔ 👆 ⚙️ `Optional` ⚖️ `Union[Something, None]` 🍵 🔢 💲, 👆 💪 ✍ 🌅 🔃 ⚫️ Pydantic 🩺 🔃 <a href="https://docs.pydantic.dev/latest/concepts/models/#required-optional-fields" class="external-link" target="_blank">✔ 📦 🏑</a>.

///

			//
			// If PodIPs exists, it is preferred, otherwise fallback to PodIP.
			//
			// If we get to this point and have a pod that really and truly has no IP in either of those,
			// it's not routable at this point and something is wrong/we should discard this event.
			podIPs := util.GetPodIPsIfPresent(pod)
			if len(podIPs) == 0 {
				log.Debugf("pod update event skipped: no IP assigned yet")
				return nil
			}