To add a function that should be run when the application is shutting down, declare it with the event `"shutdown"`:

{* ../../docs_src/events/tutorial002_py39.py hl[6] *}

Here, the `shutdown` event handler function will write a text line `"Application shutdown"` to a file `log.txt`.

/// info

In the `open()` function, the `mode="a"` means "append", so, the line will be added after whatever is on that file, without overwriting the previous contents.

// Code generated by avx512test. DO NOT EDIT.

#include "../../../../../../runtime/textflag.h"

TEXT asmtest_avx512_ifma(SB), NOSPLIT, $0
	VPMADD52HUQ X7, X11, K1, X18                       // 62e2a509b5d7
	VPMADD52HUQ X0, X11, K1, X18                       // 62e2a509b5d0
	VPMADD52HUQ 17(SP)(BP*2), X11, K1, X18             // 62e2a509b5946c11000000
	VPMADD52HUQ -7(DI)(R8*4), X11, K1, X18             // 62a2a509b59487f9ffffff

               retain an indication of any previous modifications; and

            c. indicate the Licensed Material is licensed under this
               Public License, and include the text of, or the URI or
               hyperlink to, this Public License.

       2. You may satisfy the conditions in Section 3(a)(1) in any
          reasonable manner based on the medium, means, and context in

{* ../../docs_src/first_steps/tutorial001.py *}

Скопіюйте це до файлу `main.py`.

Запустіть сервер:

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:single">main.py</u>
<font color="#3465A4">INFO    </font> Using path <font color="#3465A4">main.py</font>

// This contains the valid opcode combinations available
// in cmd/internal/obj/ppc64/asm9.go which exist for
// POWER10/ISA 3.1.

#include "../../../../../runtime/textflag.h"

TEXT asmtest(SB), DUPOK|NOSPLIT, $0
	BRD R1, R2                              // 7c220176
	BRH R1, R2                              // 7c2201b6
	BRW R1, R2                              // 7c220136

### Sobrescreva o manipulador de erro `HTTPException` { #override-the-httpexception-error-handler }

Do mesmo modo, você pode sobrescrever o `HTTPException`.

Por exemplo, você pode querer retornar uma *response* em *plain text* ao invés de um JSON para os seguintes erros:

{* ../../docs_src/handling_errors/tutorial004_py39.py hl[3:4,9:11,25] *}

/// note | Detalhes Técnicos

Each specific example `dict` in the `examples` can contain:

* `summary`: Short description for the example.
* `description`: A long description that can contain Markdown text.
* `value`: This is the actual example shown, e.g. a `dict`.
* `externalValue`: alternative to `value`, a URL pointing to the example. Although this might not be supported by as many tools as `value`.

	if err := adbCopyGoroot(); err != nil {
		return 0, err
	}

	// Prepare a temporary directory that will be cleaned up at the end.
	// Binary names can conflict.
	// E.g. template.test from the {html,text}/template packages.
	binName := filepath.Base(os.Args[1])
	deviceGotmp := fmt.Sprintf(deviceRoot+"/%s-%d", binName, os.Getpid())
	deviceGopath := deviceGotmp + "/gopath"

///

## Types and validation { #types-and-validation }

These environment variables can only handle text strings, as they are external to Python and have to be compatible with other programs and the rest of the system (and even with different operating systems, as Linux, Windows, macOS).

Un ejemplo de código Bash...

```bash
# Imprime un saludo al universo
echo "Hello universe"
```

...y un ejemplo de código de consola...

```console
$ <font color="#4E9A06">fastapi</font> run <u style="text-decoration-style:solid">main.py</u>
<span style="background-color:#009485"><font color="#D3D7CF"> FastAPI </font></span>  Starting server
        Searching for package file structure
```