Je kunt bijvoorbeeld een bestand `main.py` hebben met:

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

Het tweede argument van <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> is de standaardwaarde die wordt geretourneerd.

        /* Unless key returned is null or invalid Transport.loop() always
         * calls doRecv() after and no one else but the transport thread
         * should call doRecv(). Therefore it is ok to expect that the data
         * in sbuf will be preserved for copying into BUF in doRecv().
         */

        return key;
    }

    protected void doSend( Request request ) throws IOException {
        synchronized (BUF) {

		os.Setenv("CONSOLE_STS_DURATION", valueSts)
	} else if valueSession := env.Get(config.EnvBrowserSessionDuration, ""); valueSession != "" {
		os.Setenv("CONSOLE_STS_DURATION", valueSession)
	}

	os.Setenv("CONSOLE_MINIO_SITE_NAME", globalSite.Name())
	os.Setenv("CONSOLE_MINIO_SITE_REGION", globalSite.Region())
	os.Setenv("CONSOLE_MINIO_REGION", globalSite.Region())

	ldflagsStr += " -X github.com/minio/minio/cmd.GOPATH=" + os.Getenv("GOPATH")
	ldflagsStr += " -X github.com/minio/minio/cmd.GOROOT=" + os.Getenv("GOROOT")
	return ldflagsStr
}

// genReleaseTag prints release tag to the console for easy git tagging.
func releaseTag(version string) (string, time.Time) {
	relPrefix := "DEVELOPMENT"
	if prefix := os.Getenv("MINIO_RELEASE"); prefix != "" {
		relPrefix = prefix
	}

         * calls doRecv() after and no one else but the transport thread
         * should call doRecv(). Therefore it is ok to expect that the data
         * in sbuf will be preserved for copying into BUF in doRecv().
         */

        return (long) Encdec.dec_uint16le(this.sbuf, 34) & 0xFFFF;
    }


    @Override
    protected void doSend ( Request request ) throws IOException {

        }
    }

    private static void downloadFileFromURL(String urlString, File destination) throws Exception {
        if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
            String username = System.getenv("MVNW_USERNAME");
            char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
            Authenticator.setDefault(new Authenticator() {
                @Override

			log.Printf("failed to ping sqlDB, got error %v", err)
			os.Exit(1)
		}

		RunMigrations()
	}
}

func OpenTestConnection(cfg *gorm.Config) (db *gorm.DB, err error) {
	dbDSN := os.Getenv("GORM_DSN")
	switch os.Getenv("GORM_DIALECT") {
	case "mysql":
		log.Println("testing mysql...")
		if dbDSN == "" {
			dbDSN = mysqlDSN
		}
		db, err = gorm.Open(mysql.Open(dbDSN), cfg)
	case "postgres":

    val isCiServer = CI_ENVIRONMENT_VARIABLE in System.getenv()
    val isGhActions = "GITHUB_ACTIONS" in System.getenv()
    val isTeamCity = "TEAMCITY_VERSION" in System.getenv()
    val isTeamCityParallelTestsEnabled
        get() = "TEAMCITY_PARALLEL_TESTS_ENABLED" in System.getenv()
    val isCodeQl: Boolean by lazy {

Die Daten werden darum mit einem „neuen“ `tax`-Wert von `10.5` abgespeichert.

## Teilweises Ersetzen mit `PATCH`

Sie können auch die <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/PATCH" class="external-link" target="_blank">HTTP `PATCH`</a> Operation verwenden, um Daten *teilweise* zu ersetzen.

Das bedeutet, sie senden nur die Daten, die Sie aktualisieren wollen, der Rest bleibt unverändert.

  __path__ = [_tf_api_dir]
elif _tf_api_dir not in __path__:
  __path__.append(_tf_api_dir)

# Hook external TensorFlow modules.

# Load tensorflow-io-gcs-filesystem if enabled
if (_os.getenv("TF_USE_MODULAR_FILESYSTEM", "0") == "true" or
    _os.getenv("TF_USE_MODULAR_FILESYSTEM", "0") == "1"):
  import tensorflow_io_gcs_filesystem as _tensorflow_io_gcs_filesystem

# Lazy-load Keras v2/3.
_tf_uses_legacy_keras = (