/// note

FastAPI will know that the value of `q` is not required because of the default value `= None`.

The `str | None` (Python 3.10+) or `Union` in `Union[str, None]` (Python 3.8+) is not used by FastAPI to determine that the value is not required, it will know it's not required because it has a default value of `= None`.

## Example Lambda handler

Install the necessary dependencies.
```sh
pip install flask requests
```

Following is an example lambda handler.
```py

{!> ../../docs_src/bigger_applications/app_an_py39/dependencies.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="1  5-7" title="app/dependencies.py"
{!> ../../docs_src/bigger_applications/app_an/dependencies.py!}
```

////

//// tab | Python 3.8+ nicht annotiert

/// tip | "Tipp"

Bevorzugen Sie die `Annotated`-Version, falls möglich.

///

Например, у вас есть файл `main.py`:

```Python hl_lines="3"
import os

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

/// tip

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.

```Python hl_lines="3"
import os

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

/// tip | "Dica"

O segundo argumento para <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> é o valor padrão a ser retornado.

Se não for fornecido, é `None` por padrão, Aqui fornecemos `"World"` como o valor padrão a ser usado.

///

hlightedUnit){this.hideWidget();break}this.highlightNextUnit()}a.preventDefault(),this.updateFromElementVal();break;case 27:this.updateFromElementVal();break;case 37:a.preventDefault(),this.highlightPrevUnit(),this.updateFromElementVal();break;case 38:switch(a.preventDefault(),this.highlightedUnit){case"hour":this.incrementHour(),this.highlightHour();break;case"minute":this.incrementMinute(),this.highlightMinute();break;case"second":this.incrementSecond(),this.highlightSecond();break;case"meridi...

{!> ../../docs_src/bigger_applications/app_an_py39/dependencies.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="1  5-7" title="app/dependencies.py"
{!> ../../docs_src/bigger_applications/app_an/dependencies.py!}
```

////

//// tab | Python 3.8+ non-Annotated

/// tip | "Dica"

Prefira usar a versão `Annotated` se possível.

///

![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png)

### Faite en python moderne

Tout est basé sur la déclaration de type standard de **Python 3.8** (grâce à Pydantic). Pas de nouvelles syntaxes à apprendre. Juste du Python standard et moderne.

            // primarySetupOffset
            // SMB_COM_TRANSACTION: 61 = 32 SMB header + 1 (word count) + 28 (fixed words)
            // SMB_COM_NT_TRANSACTION: 69 = 32 SMB header + 1 (word count) + 38 (fixed words)
            this.parameterOffset = this.primarySetupOffset;

            // 2* setupCount
            this.parameterOffset += this.setupCount * 2;
            this.parameterOffset += 2; // ByteCount

![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png)

### Только современный Python

Все эти возможности основаны на стандартных **аннотациях типов Python 3.8** (благодаря Pydantic). Не нужно изучать новый синтаксис. Только лишь стандартный современный Python.