* Valida **estructuras complejas**:
    * Usa modelos jerárquicos de modelos de Pydantic, `typing` de Python,  `List` y `Dict`, etc.

    * Como as estruturas de dados do Pydantic são apenas instâncias de classes que você define, a auto completação, _linting_, _mypy_ e a sua intuição devem funcionar corretamente com seus dados validados.
* Valida **estruturas complexas**:
    * Use modelos hierárquicos do Pydantic, `List` e `Dict` do `typing` do Python, etc.

* Valide les **structures complexes**:
    * Utilise les modèles hiérarchique de Pydantic, le `typage` Python pour les `Lists`, `Dict`, etc.
    * Et les validateurs permettent aux schémas de données complexes d'être clairement et facilement définis, validés et documentés sous forme d'un schéma JSON.

                "path",
                "item_id"
            ],
            "msg": "value is not a valid integer",
            "type": "type_error.integer"
        }
    ]
}
```

eine Textversion:

```
1 validation error
path -> item_id
  value is not a valid integer (type=type_error.integer)
```

#### `RequestValidationError` vs. `ValidationError`

!!! warning "Achtung"

  `comp:` etc.  At this stage we check if the PR is valid and meets certain
  quality requirements. For example, we check if the CLA is signed, PR has
  sufficient description, if applicable unit tests are added, if it is a
  reasonable contribution (meaning it is not a single liner cosmetic PR).

**2. Valid?**

-   If the PR passes all the quality checks then we go ahead and assign a
    reviewer.

  //      implementations prior to v1.22)
  //   2. Signer whose configured maximum is shorter than the requested duration
  //   3. Signer whose configured minimum is longer than the requested duration
  //
  // The minimum valid value for expirationSeconds is 600, i.e. 10 minutes.
  //
  // +optional
  optional int32 expirationSeconds = 8;

  // usages specifies a set of key usages requested in the issued certificate.
  //

   * if no streams were processed.
   *
   * @param lastGoodStreamId the last stream ID processed, or zero if no streams were processed.
   * @param errorCode reason for closing the connection.
   * @param debugData only valid for HTTP/2; opaque debug data to send.
   */
  @Throws(IOException::class)
  fun goAway(
    lastGoodStreamId: Int,
    errorCode: ErrorCode,
    debugData: ByteArray,
  ) {
    this.withLock {

    open fun url(url: HttpUrl): Builder =
      apply {
        this.url = url
      }

    /**
     * Sets the URL target of this request.
     *
     * @throws IllegalArgumentException if [url] is not a valid HTTP or HTTPS URL. Avoid this
     *     exception by calling [HttpUrl.parse]; it returns null for invalid URLs.
     */
    open fun url(url: String): Builder {
      return url(canonicalUrl(url).toHttpUrl())
    }

the terms of this Agreement, and without further action by the parties hereto,
such provision shall be reformed to the minimum extent necessary to make such
provision valid and enforceable.

If Recipient institutes patent litigation against any entity (including a
cross-claim or counterclaim in a lawsuit) alleging that the Program itself

FastAPI will now:

* **Validate** the data making sure that the max length is 50 characters
* Show a **clear error** for the client when the data is not valid
* **Document** the parameter in the OpenAPI schema *path operation* (so it will show up in the **automatic docs UI**)