# Body - Campos { #body-fields }

De la misma manera que puedes declarar validaciones adicionales y metadatos en los parámetros de las *path operation function* con `Query`, `Path` y `Body`, puedes declarar validaciones y metadatos dentro de los modelos de Pydantic usando `Field` de Pydantic.

## Importar `Field` { #import-field }

Primero, tienes que importarlo:

{* ../../docs_src/body_fields/tutorial001_an_py310.py hl[4] *}

/// warning | Advertencia

                final java.util.function.Function<org.lastaflute.job.subsidiary.SnapshotExecState, RESULT> oneArgLambda) {
            return OptionalThing.empty();
        }

        @Override
        public org.dbflute.optional.OptionalThingIfPresentAfter ifExecutingNow(
                final java.util.function.Consumer<org.lastaflute.job.subsidiary.SnapshotExecState> oneArgLambda) {

 * under the License.
 */
package org.apache.maven.lifecycle.mapping;

import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import static java.util.function.Function.identity;
import static java.util.stream.Collectors.toMap;

/**
 * DefaultLifecycleMapping
 */
public class DefaultLifecycleMapping implements LifecycleMapping {

    private List<Lifecycle> lifecycles;

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.BiConsumer;
import java.util.function.IntToDoubleFunction;
import java.util.function.Supplier;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**

* path operation
* path operation decorator
* path operation function

* body
* request body
* response body
* JSON body
* form body
* file body
* function body

* parameter
* body parameter
* path parameter
* query parameter
* cookie parameter
* header parameter
* form parameter
* function parameter

* event
* startup event
* server'ın startup'ı

8. Nota que esta *path operation function* usa `def` regular en lugar de `async def`.

    Como siempre, en FastAPI puedes combinar `def` y `async def` según sea necesario.

    Si necesitas un repaso sobre cuándo usar cuál, revisa la sección _"¿Con prisa?"_ en la documentación sobre [`async` y `await`](../async.md#in-a-hurry).

  }

  public <F extends Enum<F> & Function<String, Integer> & Iterable<Long>>
      void testResolveType_fromTypeVariable() {
    TypeToken<?> f = TypeToken.of(new TypeCapture<F>() {}.capture());
    assertEquals(String.class, f.resolveType(Function.class.getTypeParameters()[0]).getType());
    assertEquals(Integer.class, f.resolveType(Function.class.getTypeParameters()[1]).getType());

Template içinde `url_for()` da kullanabilirsiniz; argüman olarak, *path operation function*'ınızın kullandığı argümanların aynısını alır.

Dolayısıyla şu bölüm:

{% raw %}

```jinja
<a href="{{ url_for('read_item', id=id) }}">
```

{% endraw %}

...*path operation function* olan `read_item(id=id)` tarafından handle edilecek URL'nin aynısına bir link üretir.

- Added support for projected volume in describe function  ([#70158](https://github.com/kubernetes/kubernetes/pull/70158), [@WanLinghao](https://github.com/WanLinghao))

    return asByteSource(file).read(processor);
  }

  /**
   * Computes the hash code of the {@code file} using {@code hashFunction}.
   *
   * @param file the file to read
   * @param hashFunction the hash function to use to hash the data
   * @return the {@link HashCode} of all of the bytes in the file
   * @throws IOException if an I/O error occurs
   * @since 12.0