### 在使用 `yield` 的依赖项中使用上下文管理器

/// warning | 注意

这是一个更为"高级"的想法。

如果你刚开始使用 **FastAPI** ，你可以暂时可以跳过它。

///

在Python中，你可以通过<a href="https://docs.python.org/3/reference/datamodel.html#context-managers" class="external-link" target="_blank">创建一个带有`__enter__()`和`__exit__()`方法的类</a>来创建上下文管理器。

你也可以在 **FastAPI** 的 `yield` 依赖项中通过 `with` 或者 `async with` 语句来使用它们：

```Python hl_lines="1-9  13"

    std::unique_ptr<TF_Status, decltype(&TF_DeleteStatus)> await_status(
        TF_NewStatus(), TF_DeleteStatus);
    // Wait until all pending nodes have completed since they may have a
    // reference to default_cancellation_manager_. We ignore the status return
    // since we already have a bad status to propagate.
    TFE_ContextAsyncWait(context, await_status.get());

   a jurisdiction where the defendant maintains its principal place of business
   and such litigation shall be governed by laws of that jurisdiction, without
   reference to its conflict-of-law provisions. Nothing in this Section shall
   prevent a party’s ability to bring cross-claims or counter-claims.

9. Miscellaneous

    return warmUp(cache, WARMUP_MIN, WARMUP_MAX);
  }

  /**
   * Returns the entries that were added to the map, so they won't fall out of a map with weak or
   * soft references until the caller drops the reference to the returned entries.
   */
  private List<Entry<Object, Object>> warmUp(
      LoadingCache<Object, Object> cache, int minimum, int maximum) {

    List<Entry<Object, Object>> entries = Lists.newArrayList();

  //   Requests for this signer are never auto-approved by kube-controller-manager, and can be issued by the "csrsigning" controller in kube-controller-manager.
  //
  // More details are available at https://k8s.io/docs/reference/access-authn-authz/certificate-signing-requests/#kubernetes-signers
  //
  // Custom signerNames can also be specified. The signer defines:
  //  1. Trust distribution: how trust (CA bundles) are distributed.

        // timing of executing the interpolation

        try
        {
        new RegexBasedModelInterpolator().interpolate( model, context );
        fail( "Should have failed to interpolate with invalid reference" );
        }
        catch ( ModelInterpolationException expected )
        {
        assertTrue( true );
        }
        */

        ModelInterpolator interpolator = createInterpolator();

		return nil
	}

	config.RLock()
	defer config.RUnlock()

	var tierCfgs []madmin.TierConfig
	for _, tier := range config.Tiers {
		// This makes a local copy of tier config before
		// passing a reference to it.
		tier := tier.Clone()
		tierCfgs = append(tierCfgs, tier)
	}
	return tierCfgs
}

// Edit replaces the credentials of the remote tier specified by tierName with creds.

  // into the ResourceClaim that gets created from this template. The
  // same fields as in a ResourceClaim are also valid here.
  optional ResourceClaimSpec spec = 2;
}

// ResourceClass is used by administrators to influence how resources
// are allocated.
//
// This is an alpha type and requires enabling the DynamicResourceAllocation
// feature gate.
message ResourceClass {
  // Standard object metadata
  // +optional

///

/// warning

Make sure to **always** use the **exec form** of the `CMD` instruction, as explained below.

///

#### Use `CMD` - Exec Form

The <a href="https://docs.docker.com/reference/dockerfile/#cmd" class="external-link" target="_blank">`CMD`</a> Docker instruction can be written using two forms:

✅ **Exec** form:

```Dockerfile
# ✅ Do this
CMD ["fastapi", "run", "app/main.py", "--port", "80"]

   * addresses, the output follows <a href="http://tools.ietf.org/html/rfc5952">RFC 5952</a> section
   * 4. The main difference is that this method uses "::" for zero compression, while Java's version
   * uses the uncompressed form (except on Android, where the zero compression is also done). The
   * other difference is that this method outputs any scope ID in the format that it was provided at