{* ../../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 }

If you have a *path operation* that receives a *path parameter*, but you want the possible valid *path parameter* values to be predefined, you can use a standard Python <abbr title="Enumeration">`Enum`</abbr>.

### Create an `Enum` class { #create-an-enum-class }

   *
   * @param url the URL to read from
   * @param charset the charset used to decode the input stream; see {@link StandardCharsets} for
   *     helpful predefined constants
   * @return a string containing all the characters from the URL
   * @throws IOException if an I/O error occurs.
   */
  public static String toString(URL url, Charset charset) throws IOException {

   *
   * @param file the file to read from
   * @param charset the charset used to decode the input stream; see {@link StandardCharsets} for
   *     helpful predefined constants
   * @return the buffered reader
   */
  public static BufferedReader newReader(File file, Charset charset) throws FileNotFoundException {
    checkNotNull(file);
    checkNotNull(charset);

package jstream

import (
	"fmt"
	"strconv"
)

// Predefined errors
var (
	ErrSyntax        = DecoderError{msg: "invalid character"}
	ErrUnexpectedEOF = DecoderError{msg: "unexpected end of JSON input"}
	ErrMaxDepth      = DecoderError{msg: "maximum recursion depth exceeded"}
)

type errPos [2]int // line number, byte offset where error occurred

// DecoderError contains a detailed decoding error.
type DecoderError struct {

}

var (
	D        MultiFlag
	I        MultiFlag
	PrintOut int
	DebugV   bool
)

func init() {
	flag.Var(&D, "D", "predefined symbol with optional simple value -D=identifier=value; can be set multiple times")
	flag.Var(&I, "I", "include directory; can be set multiple times")
	flag.BoolVar(&DebugV, "v", false, "print debug output")

* `needy`, zorunlu bir `str`.
* `skip`, varsayılan değeri `0` olan bir `int`.
* `limit`, isteğe bağlı bir `int`.

/// tip | İpucu

[Path Parametreleri](path-params.md#predefined-values) ile aynı şekilde `Enum`'ları da kullanabilirsiniz.

* `skip`, un `int` con un valor por defecto de `0`.
* `limit`, un `int` opcional.

/// tip | Consejo

También podrías usar `Enum`s de la misma manera que con [Parámetros de Path](path-params.md#predefined-values).

* `needy`, um `str` obrigatório.
* `skip`, um `int` com o valor padrão `0`.
* `limit`, um `int` opcional.

/// tip | Dica

Você também poderia usar `Enum`s da mesma forma que com [Parâmetros de rota](path-params.md#predefined-values).

* `skip`, `int` зі значенням за замовчуванням `0`.
* `limit`, необов’язковий `int`.

/// tip | Порада

Ви також можете використовувати `Enum` так само, як і з [Параметри шляху](path-params.md#predefined-values).

{* ../../docs_src/query_params/tutorial006_py310.py hl[8] *}

在此例中，有 3 個查詢參數：

* `needy`，必填的 `str`。
* `skip`，具有預設值 `0` 的 `int`。
* `limit`，選填的 `int`。

/// tip | 提示

你也可以像在[路徑參數](path-params.md#predefined-values)中一樣使用 `Enum`。