예를 들어 다음과 같은 `main.py` 파일이 있다고 합시다:

```Python hl_lines="3"
import os

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

/// tip | 팁

<a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> 의 두 번째 인자는 반환할 기본값입니다.

여기서는 `"World"`를 넣었기에 기본값으로써 사용됩니다. 넣지 않으면 `None` 이 기본값으로 사용됩니다.

///

그러면 해당 파이썬 프로그램을 다음과 같이 호출할 수 있습니다:

import os

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

/// tip | Совет

Второй аргумент <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> - это возвращаемое по умолчанию значение.

Если значение не указано, то по умолчанию оно равно `None`. В данном случае мы указываем `«World»` в качестве значения по умолчанию.

///

 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.maven.embedder;

/**
 * Hello world!
 *
 */
public class App
{
    public static void main( String[] args )
    {
        System.out.println( "Hello World!" );
    }

	// local to remote
	remoteConn := local.Connection(remoteHost)
	remoteConn.WaitForConnect(t.Context())
	defer testlogger.T.SetErrorTB(t)()

	t.Run("localToRemote", func(t *testing.T) {
		const testPayload = "Hello Grid World!"

		start := time.Now()
		resp, err := remoteConn.Request(t.Context(), handlerTest, []byte(testPayload))
		errFatal(err)
		if string(resp) != testPayload {
			t.Errorf("want %q, got %q", testPayload, string(resp))
		}

@app.get("/", dependencies=[Depends(bearer_scheme)])
async def get_root():
    return {"message": "Hello, World!"}


client = TestClient(app)


def test_get_root():
    response = client.get("/", headers={"Authorization": "Bearer token"})
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Hello, World!"}


def test_get_root_no_token():
    response = client.get("/")

```txt
Hello, World from Flask!
```

А если вы перейдёте по <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a>, вы увидите HTTP‑ответ от FastAPI:

```JSON
{
    "message": "Hello World"
}

from markupsafe import escape

flask_app = Flask(__name__)


@flask_app.route("/")
def flask_main():
    name = request.args.get("name", "World")
    return f"Hello, {escape(name)} from Flask!"


app = FastAPI()


@app.get("/v2")
def read_main():
    return {"message": "Hello World"}

@app.get("/", dependencies=[Depends(parent_dep)])
async def get_main():
    return {"msg": "Hello World"}


client = TestClient(app)


def test_dependency_set_status_code():
    response = client.get("/")
    assert response.status_code == 201, response.text

```txt
Hello, World from Flask!
```

E se você for até <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a>, você verá o retorno do FastAPI:

```JSON
{
    "message": "Hello World"
}

```txt
Hello, World from Flask!
```

Und wenn Sie auf <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a> gehen, sehen Sie die Response von FastAPI:

```JSON
{
    "message": "Hello World"
}