Посмотрим, как это работает, и как это изменить при необходимости.

## Pydantic‑модели для входа и выхода { #pydantic-models-for-input-and-output }

Предположим, у вас есть Pydantic‑модель со значениями по умолчанию, как здесь:

{* ../../docs_src/separate_openapi_schemas/tutorial001_py310.py ln[1:7] hl[7] *}

### Модель для входа { #model-for-input }

Если использовать эту модель как входную, как здесь:

from typing import Optional, Union

import pytest
from fastapi.openapi.models import Schema, SchemaType


@pytest.mark.parametrize(
    "type_value",
    [
        "array",
        ["string", "null"],
        None,
    ],
)
def test_allowed_schema_type(
    type_value: Optional[Union[SchemaType, list[SchemaType]]],
) -> None:
    """Test that Schema accepts SchemaType, List[SchemaType] and None for type field."""

 * under the License.
 */
package org.apache.maven.model.normalization;

import org.apache.maven.model.Model;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelProblemCollector;

/**
 * Handles normalization of a model. In this context, normalization is the process of producing a canonical
 * representation for models that physically look different but are semantically equivalent.
 *

</div>

### Modell für die Ausgabe { #model-for-output }

Wenn Sie jedoch dasselbe Modell als Ausgabe verwenden, wie hier:

{* ../../docs_src/separate_openapi_schemas/tutorial001_py310.py hl[19] *}

... dann, weil `description` einen Defaultwert hat, wird es, wenn Sie für dieses Feld **nichts zurückgeben**, immer noch diesen **Defaultwert** haben.

     */
    private static class MockModelBuilderResult implements ModelBuilderResult {
        private final Model effectiveModel;
        private final Model rawModel;
        private final Model fileModel;

        MockModelBuilderResult(Model effectiveModel, Model rawModel, Model fileModel) {
            this.effectiveModel = effectiveModel;
            this.rawModel = rawModel;

 */
package org.apache.maven.model.composition;

import javax.inject.Named;
import javax.inject.Singleton;

import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import org.apache.maven.model.Dependency;
import org.apache.maven.model.DependencyManagement;
import org.apache.maven.model.Model;
import org.apache.maven.model.building.ModelBuildingRequest;

    page.get_by_role("button", name="GET /items/ Read Items").click()
    page.get_by_role("button", name="Try it out").click()
    # Manually add the screenshot
    page.screenshot(path="docs/en/docs/img/tutorial/header-param-models/image01.png")

    # ---------------------
    context.close()
    browser.close()


process = subprocess.Popen(
    ["fastapi", "run", "docs_src/header_param_models/tutorial001.py"]
)
try:

    page.get_by_role("button", name="POST /login/ Login").click()
    page.get_by_role("button", name="Try it out").click()
    # Manually add the screenshot
    page.screenshot(path="docs/en/docs/img/tutorial/request-form-models/image01.png")

    # ---------------------
    context.close()
    browser.close()


process = subprocess.Popen(
    ["fastapi", "run", "docs_src/request_form_models/tutorial001.py"]
)
try:

Import `BaseSettings` from Pydantic and create a sub-class, very much like with a Pydantic model.

The same way as with Pydantic models, you declare class attributes with type annotations, and possibly default values.

You can use all the same validation features and tools you use for Pydantic models, like different data types and additional validations with `Field()`.

 */
package org.apache.maven.model.composition;

import java.util.List;

import org.apache.maven.model.DependencyManagement;
import org.apache.maven.model.Model;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelProblemCollector;

/**
 * Handles the import of dependency management from other models into the target model.
 *