El manejador de excepciones recibirá un `Request` y la excepción.

{* ../../docs_src/handling_errors/tutorial004.py hl[2,14:16] *}

Ahora, si vas a `/items/foo`, en lugar de obtener el error JSON por defecto con:

```JSON
{
    "detail": [
        {
            "loc": [
                "path",
                "item_id"

///

### Declarar un *path parameter*

Luego crea un *path parameter* con una anotación de tipo usando la clase enum que creaste (`ModelName`):

{* ../../docs_src/path_params/tutorial005.py hl[16] *}

### Revisa la documentación

Como los valores disponibles para el *path parameter* están predefinidos, la documentación interactiva puede mostrarlos de manera ordenada:

Para sobrescrevê-lo, importe o `RequestValidationError` e use-o com o `@app.exception_handler(RequestValidationError)` para decorar o manipulador de exceções.

{* ../../docs_src/handling_errors/tutorial004.py hl[2,14:16] *}

Se você for ao `/items/foo`, em vez de receber o JSON padrão com o erro:

```JSON
{
    "detail": [
        {
            "loc": [
                "path",
                "item_id"

    /** Permission to write file attributes */
    public static final int FILE_WRITE_ATTRIBUTES = 0x00000100; // 9
    /** Standard delete permission */
    public static final int DELETE = 0x00010000; // 16
    /** Permission to read the security descriptor */
    public static final int READ_CONTROL = 0x00020000; // 17
    /** Permission to write the discretionary access control list */

        byte[] buffer = new byte[10];

        // Act
        int bytesWritten = transPeekNamedPipe.writeSetupWireFormat(buffer, 0);

        // Assert
        assertEquals(4, bytesWritten);
        // -1 in 16-bit is 0xFFFF
        assertEquals((byte) 0xFF, buffer[2]);
        assertEquals((byte) 0xFF, buffer[3]);
    }

    @Test
    @DisplayName("Should verify all read methods return 0 with various parameters")

        this.file = file;
        this.openFlags = openFlags & 0xFFFF;
        this.access = openFlags >>> 16 & 0xFFFF;
        if (file.type != SmbFile.TYPE_NAMED_PIPE) {
            file.open(openFlags, access, SmbFile.ATTR_NORMAL, 0);
            this.openFlags &= ~(SmbFile.O_CREAT | SmbFile.O_TRUNC);
        } else {

🔐 ⚫️, 🗄 `RequestValidationError` & ⚙️ ⚫️ ⏮️ `@app.exception_handler(RequestValidationError)` 🎀 ⚠ 🐕‍🦺.

⚠ 🐕‍🦺 🔜 📨 `Request` & ⚠.

{* ../../docs_src/handling_errors/tutorial004.py hl[2,14:16] *}

🔜, 🚥 👆 🚶 `/items/foo`, ↩️ 💆‍♂ 🔢 🎻 ❌ ⏮️:

```JSON
{
    "detail": [
        {
            "loc": [
                "path",
                "item_id"
            ],

	_ = x[ErrInvalidBucketName-11]
	_ = x[ErrInvalidDigest-12]
	_ = x[ErrInvalidRange-13]
	_ = x[ErrInvalidRangePartNumber-14]
	_ = x[ErrInvalidCopyPartRange-15]
	_ = x[ErrInvalidCopyPartRangeSource-16]
	_ = x[ErrInvalidMaxKeys-17]
	_ = x[ErrInvalidEncodingMethod-18]
	_ = x[ErrInvalidMaxUploads-19]
	_ = x[ErrInvalidMaxParts-20]
	_ = x[ErrInvalidPartNumberMarker-21]
	_ = x[ErrInvalidPartNumber-22]

Обробник помилок отримує `Request` і саму помилку.

{* ../../docs_src/handling_errors/tutorial004.py hl[2,14:16] *}

Тепер, якщо Ви перейдете за посиланням `/items/foo`, замість того, щоб отримати стандартну JSON-помилку:

```JSON
{
    "detail": [
        {
            "loc": [
                "path",

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