# We enable this in the nightly and release builds because before uploading the
# wheels, we install them in a virtual environment and run some smoke tests on
# it. TFCI Mac VMs only have one Python version installed so we need to install
# the other versions manually.
if [[ "${TFCI_MACOS_PYENV_INSTALL_ENABLE}" == 1 ]]; then
  # Install the necessary Python, unless it's already present

	// down `ch`
	go func() {
		for {
		outerLoop:
			watchCh := ies.client.Watch(ctx,
				keyPath, etcd.WithPrefix(), etcd.WithKeysOnly())

			for {
				select {
				case <-ctx.Done():
					return
				case watchResp, ok := <-watchCh:
					if !ok {
						time.Sleep(1 * time.Second)
						// Upon an error on watch channel
						// re-init the watch channel.
						goto outerLoop
					}

	ErrNoSecretKeyWithAccessKey = fmt.Errorf("secret key must be specified if access key is specified")
	ErrContainsReservedChars    = fmt.Errorf("access key contains one of reserved characters '=' or ','")
)

// AnonymousCredentials simply points to empty credentials
var AnonymousCredentials = Credentials{}

print(f"Hello {name} from Python")
```

/// tip

第二個參數是 <a href="https://docs.python.org/zh-tw/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> 的預設回傳值。

如果沒有提供，預設值為 `None`，這裡我們提供 `"World"` 作為預設值。

///

然後你可以呼叫這個 Python 程式：

//// tab | Linux, macOS, Windows Bash

<div class="termy">

```console
// 這裡我們還沒有設定環境變數
$ python main.py

// 因為我們沒有設定環境變數，所以我們得到的是預設值

	sort.Strings(paths)
	n := uniq(sort.StringSlice(paths))
	return paths[:n]
}

// Init sets the trimStrings to possible GOPATHs
// and GOROOT directories. Also append github.com/minio/minio
// This is done to clean up the filename, when stack trace is
// displayed when an error happens.
func Init(goPath string, goRoot string) {
	var goPathList []string
	var goRootList []string
	var defaultgoPathList []string

//// tab | Test

Hier einige Dinge, die in HTML-„abbr“-Elemente gepackt sind (einige sind erfunden):

### Das abbr gibt eine vollständige Phrase { #the-abbr-gives-a-full-phrase }

* <abbr title="Getting Things Done – Dinge erledigt bekommen">GTD</abbr>
* <abbr title="less than – kleiner als"><code>lt</code></abbr>
* <abbr title="XML Web Token">XWT</abbr>
* <abbr title="Paralleles Server-Gateway-Interface">PSGI</abbr>

// SelectStatement is the top level parsed and analyzed structure
type SelectStatement struct {
	selectAST *Select

	// Analysis result of the statement
	selectQProp qProp

	// Result of parsing the limit clause if one is present
	// (otherwise -1)
	limitValue int64

	// Count of rows that have been output.
	outputCount int64

	// Table alias
	tableAlias string
}

			}
		case <-keepAliveTicker.C:
			if len(diffCh) > 0 {
				continue
			}
			if _, err := w.Write([]byte(" ")); err != nil {
				return
			}
			xhttp.Flush(w)
		case <-ctx.Done():
			return
		}
	}
}

// ReplicationMRFHandler - POST returns info on entries in the MRF backlog for a node or all nodes

	      <Event>s3:ObjectCreated:Put</Event>
	   </CloudFunctionConfiguration>
	   <TopicConfiguration>
	      <Topic>arn:aws:sns:us-west-2:444455556666:sns-notification-one</Topic>
	      <Event>s3:ObjectCreated:*</Event>
	  </TopicConfiguration>
	</NotificationConfiguration>
	`)

ここでは<a href="https://gunicorn.org/" class="external-link" target="_blank">**Gunicorn**</a>が**Uvicornのワーカー・プロセス**を管理する場合の使い方について紹介していきます。

/// info

<!-- NOTE: the current version of docker.md is outdated compared to English one.  -->
DockerやKubernetesなどのコンテナを使用している場合は、次の章で詳しく説明します： [コンテナ内のFastAPI - Docker](docker.md){.internal-link target=_blank}

特に**Kubernetes**上で実行する場合は、おそらく**Gunicornを使用せず**、**コンテナごとに単一のUvicornプロセス**を実行することになりますが、それについてはこの章の後半で説明します。