* Si on n'utilisait pas FastAPI mais directement Starlette (ou un outil équivalent comme Sanic, Flask, Responder, etc) il faudrait implémenter la validation des données et la sérialisation par nous-même. Le résultat serait donc le même dans...

/// info

To use `EmailStr`, first install <a href="https://github.com/JoshData/python-email-validator" class="external-link" target="_blank">`email-validator`</a>.

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then install it, for example:

```console
$ pip install email-validator
```

or with:

```console
$ pip install "pydantic[email]"
```

///

## Rajouter plus de validation

Vous pouvez aussi rajouter un second paramètre `min_length` :

{* ../../docs_src/query_params_str_validations/tutorial003.py hl[9] *}

## Ajouter des validations par expressions régulières

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.searchlog;

import org.lastaflute.web.validation.Required;
import org.lastaflute.web.validation.theme.conversion.ValidateTypeFailure;

import jakarta.validation.constraints.Size;

/**
 * The edit form for Search Log.
 * This form handles the editing of search log entries in the administration interface.
 */

    * If you didn't use FastAPI and used Starlette directly (or another tool, like Sanic, Flask, Responder, etc) you would have to implement all the data validation and serialization yourself. So, your final application would still have...

        byte[] expectedHash = preauthService.getCurrentPreauthHash(sessionId);

        // Validation should pass with correct hash
        assertTrue(preauthService.validatePreauthIntegrity(sessionId, expectedHash));

        // Validation should fail with incorrect hash
        byte[] incorrectHash = new byte[expectedHash.length];
        secureRandom.nextBytes(incorrectHash);

}
```

Again, doing just that declaration, with **FastAPI** you get:

* Editor support (completion, etc.), even for nested models
* Data conversion
* Data validation
* Automatic documentation

## Special types and validation { #special-types-and-validation }

Apart from normal singular types like `str`, `int`, `float`, etc. you can use more complex singular types that inherit from `str`.

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.crawlinginfo;

import org.lastaflute.web.validation.Required;
import org.lastaflute.web.validation.theme.conversion.ValidateTypeFailure;

import jakarta.validation.constraints.Size;

/**
 * Form class for editing crawling information in the admin interface.
 * This form handles the editing of crawling session data, which tracks

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.dict.stopwords;

import org.lastaflute.web.validation.Required;
import org.lastaflute.web.validation.theme.conversion.ValidateTypeFailure;

/**
 * Form class for editing stopwords dictionary entries in the admin interface.

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.relatedquery;

import org.lastaflute.web.validation.Required;
import org.lastaflute.web.validation.theme.conversion.ValidateTypeFailure;

import jakarta.validation.constraints.Size;

/**
 * The edit form for Related Query.
 * This form extends CreateForm and adds fields necessary for editing existing related query entries.