# Body - Fields { #body-fields }

The same way you can declare additional validation and metadata in *path operation function* parameters with `Query`, `Path` and `Body`, you can declare validation and metadata inside of Pydantic models using Pydantic's `Field`.

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

First, you have to import it:

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


/// warning

            this.result = buf.dec_ndr_long();
        } else { /* Bind_ack or Response */
            decode_out(buf);
        }
    }

    /**
     * Get the operation number for this DCERPC message.
     * @return the operation number
     */
    public abstract int getOpnum();

    /**
     * Encode the input parameters for this DCERPC message.
     * @param buf the buffer to encode into

/// tip

You can set a dependency override for a dependency used anywhere in your **FastAPI** application.

The original dependency could be used in a *path operation function*, a *path operation decorator* (when you don't use the return value), a `.include_router()` call, etc.

FastAPI will still be able to override it.

///

Similarly, you cannot redefine a path operation:

{* ../../docs_src/path_params/tutorial003b_py310.py hl[6,11] *}

The first one will always be used since the path matches first.

## Predefined values { #predefined-values }

    /**
     * Creates a new CreateForm instance.
     */
    public CreateForm() {
        // Default constructor
    }

    /**
     * The CRUD operation mode for this form.
     * Indicates whether this is a create, read, update, or delete operation.
     */
    @ValidateTypeFailure
    public Integer crudMode;

    /**
     * The name of the access token.

 * need for a distinct {@code ImmutableBiMultimap} type.
 *
 * <p><a id="iteration"></a>
 *
 * <p><b>Key-grouped iteration.</b> All view collections follow the same iteration order. In all
 * current implementations, the iteration order always keeps multiple entries with the same key
 * together. Any creation method that would customarily respect insertion order (such as {@link

import (
	"fmt"
	"os"
	"path"
)

// Wrapper functions to os.RemoveAll, which calls reliableRemoveAll
// this is to ensure that if there is a racy parent directory
// create in between we can simply retry the operation.
func removeAll(dirPath string) (err error) {
	if dirPath == "" {
		return errInvalidArgument
	}

	if err = checkPathLength(dirPath); err != nil {
		return err
	}

func (a adminAPIHandlers) SRPeerBucketOps(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

	objectAPI, _ := validateAdminReq(ctx, w, r, policy.SiteReplicationOperationAction)
	if objectAPI == nil {
		return
	}

	vars := mux.Vars(r)
	bucket := vars["bucket"]
	operation := madmin.BktOp(vars["operation"])

	var err error
	switch operation {

///

Lors de la création d’une API, le « chemin » est la manière principale de séparer les « préoccupations » et les « ressources ».

#### Opération { #operation }

« Opération » fait ici référence à l’une des « méthodes » HTTP.

L’une de :

* `POST`
* `GET`
* `PUT`
* `DELETE`

... et les plus exotiques :

* `OPTIONS`
* `HEAD`

     * Maybe semantics packet flag
     */
    int RPC_C_PF_MAYBE = 0x04;
    /**
     * Idempotent operation packet flag
     */
    int RPC_C_PF_IDEMPOTENT = 0x08;
    /**
     * Broadcast with maybe semantics packet flag
     */
    int RPC_C_PF_BROADCAST_MAYBE = 0x10;
    /**
     * Not idempotent operation packet flag
     */
    int RPC_C_PF_NOT_IDEMPOTENT = 0x20;
    /**