Por ejemplo, para declarar un valor de metadato `title` para el parámetro de path `item_id` puedes escribir:

{* ../../docs_src/path_params_numeric_validations/tutorial001_an_py310.py hl[10] *}

/// note | Nota

Un parámetro de path siempre es requerido ya que tiene que formar parte del path. Incluso si lo declaras con `None` o le asignas un valor por defecto, no afectará en nada, siempre será requerido.

///

//go:generate stringer -type=STSErrorCode -trimprefix=Err $GOFILE

// Error codes, non exhaustive list - http://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRoleWithSAML.html
const (
	ErrSTSNone STSErrorCode = iota
	ErrSTSAccessDenied
	ErrSTSMissingParameter
	ErrSTSInvalidParameterValue
	ErrSTSWebIdentityExpiredToken
	ErrSTSClientGrantsExpiredToken
	ErrSTSInvalidClientGrantsToken
	ErrSTSMalformedPolicyDocument

package cmd

import (
	"context"
	"errors"
	"fmt"
	"path"
	"strings"
	"time"

	"github.com/minio/pkg/v3/console"
)

type scanStatus uint8

const (
	scanStateNone scanStatus = iota
	scanStateStarted
	scanStateSuccess
	scanStateError

	// Time in which the initiator of a scan must have reported back.
	metacacheMaxRunningAge = time.Minute

// not as the type of a variable.
type comparable interface{ comparable }

// iota is a predeclared identifier representing the untyped integer ordinal
// number of the current const specification in a (usually parenthesized)
// const declaration. It is zero-indexed.
const iota = 0 // Untyped int.

// nil is a predeclared identifier representing the zero value for a

	rs.Bucket = bucket
	rs.Object = fi.Name
}

type rstats []*rebalanceStats

//go:generate stringer -type=rebalStatus -trimprefix=rebal $GOFILE
type rebalStatus uint8

const (
	rebalNone rebalStatus = iota
	rebalStarted
	rebalCompleted
	rebalStopped
	rebalFailed
)

type rebalanceInfo struct {
	StartTime time.Time   `msg:"startTs"` // Time at which rebalance-start was issued

{* ../../docs_src/query_params/tutorial002_py310.py hl[7] *}

En este caso, el parámetro de función `q` será opcional y será `None` por defecto.

/// check | Revisa

Además, nota que **FastAPI** es lo suficientemente inteligente para notar que el parámetro de path `item_id` es un parámetro de path y `q` no lo es, por lo tanto, es un parámetro de query.

///

	if f.IsEmpty() {
		return errXMLNotWellFormed
	}
	// A Filter must have exactly one of Prefix, Tag,
	// ObjectSize{LessThan,GreaterThan} or And specified.
	type predType uint8
	const (
		nonePred predType = iota
		prefixPred
		andPred
		tagPred
		sizeLtPred
		sizeGtPred
	)
	var predCount int
	var pType predType
	if !f.And.isEmpty() {
		pType = andPred
		predCount++
	}
	if f.Prefix.set {

Para fazer isso, use a anotação de tipo padrão do Python <a href="https://docs.python.org/3/library/typing.html#typing.Union" class="external-link" target="_blank">`typing.Union`</a>:

/// note | Nota

}

var globalScannerMetrics scannerMetrics

const (
	// START Realtime metrics, that only to records
	// last minute latencies and total operation count.
	scannerMetricReadMetadata scannerMetric = iota
	scannerMetricCheckMissing
	scannerMetricSaveUsage
	scannerMetricApplyAll
	scannerMetricApplyVersion
	scannerMetricTierObjSweep
	scannerMetricHealCheck
	scannerMetricILM
	scannerMetricCheckReplication

	}
	return true
}

// BitrotAlgorithm specifies a algorithm used for bitrot protection.
type BitrotAlgorithm uint

const (
	// SHA256 represents the SHA-256 hash function
	SHA256 BitrotAlgorithm = 1 + iota
	// HighwayHash256 represents the HighwayHash-256 hash function
	HighwayHash256
	// HighwayHash256S represents the Streaming HighwayHash-256 hash function
	HighwayHash256S