# Introduction aux Types Python

Python supporte des annotations de type (ou *type hints*) optionnelles.

Ces annotations de type constituent une syntaxe spéciale qui permet de déclarer le <abbr title="par exemple : str, int, float, bool">type</abbr> d'une variable.

En déclarant les types de vos variables, cela permet aux différents outils comme les éditeurs de texte d'offrir un meilleur support.

/**
 * A tuple of five values.
 *
 * @author koichik
 * @param <T1>
 *            The type of the first value
 * @param <T2>
 *            The type of the second value
 * @param <T3>
 *            The type of the third value
 * @param <T4>
 *            The type of the fourth value
 * @param <T5>
 *            The type of the fifth value
 */
public class Tuple5<T1, T2, T3, T4, T5> {

    /** The first value */

   */
  public static <T> Class<T> wrap(Class<T> type) {
    checkNotNull(type);

    // cast is safe: long.class and Long.class are both of type Class<Long>
    @SuppressWarnings("unchecked")
    Class<T> wrapped = (Class<T>) PRIMITIVE_TO_WRAPPER_TYPE.get(type);
    return (wrapped == null) ? type : wrapped;
  }

  /**
   * Returns the corresponding primitive type of {@code type} if it is a wrapper type; otherwise

package clause

import "gorm.io/gorm/utils"

type JoinType string

const (
	CrossJoin JoinType = "CROSS"
	InnerJoin JoinType = "INNER"
	LeftJoin  JoinType = "LEFT"
	RightJoin JoinType = "RIGHT"
)

type JoinTarget struct {
	Type        JoinType
	Association string
	Subquery    Expression
	Table       string
}

func Has(name string) JoinTarget {
	return JoinTarget{Type: InnerJoin, Association: name}
}

   * Returns a new array of the given length with the specified component type.
   *
   * @param type the component type
   * @param length the length of the new array
   */
  @GwtIncompatible // Array.newInstance(Class, int)
  @SuppressWarnings("unchecked")
  public static <T extends @Nullable Object> T[] newArray(Class<@NonNull T> type, int length) {
    return (T[]) Array.newInstance(type, length);
  }

  /**

    // Base64 encoded Type 1 message: NTLMSSP, Type 1, flags=0x00088207
    // Domain="DOMAIN", Workstation="WORKSTATION"
    private final String type1MessageBase64 = "TlRMTVNTUAABAAAABzIAAAYABgArAAAACwALACAAAABET01BSU5XT1JLU1RBVElPTg==";

    // Base64 encoded Type 3 message: NTLMSSP, Type 3
    // User: "user", Domain: "DOMAIN", Workstation: "WORKSTATION"
    // This is a valid Type 3 message with proper structure

1/xl.meta XL2 Æ b ¨Versions‘‚¤Type ¥V2ObjÞ ¢IDÄ ¤DDirÄ ÔLã°ê8EÒŸˆ”Ù Sé6¦EcAlgo £EcM £EcN §EcBSizeÒ §EcIndex ¦EcDistš ¨CSumAlgo ¨PartNums‘ ©PartETags‘ ©PartSizes‘Ò 'ªPartASizes‘Ò '¤SizeÒ 'Â¥MTimeÓ ¿W '’žÉ§MetaSys ¼X-Minio-Internal-actual-sizeÄ 141250§MetaUsr‚¤etagÙ"51fe09d68bacc8c5a68a-1¬content-type¸application/octet-streamÎöa‰ 10/xl.meta XL2 Æ b ¨Versions‘‚¤Type ¥V2ObjÞ ¢IDÄ ¤DDirÄ ÔLã°ê8EÒŸˆ”Ù Sé6¦EcAlgo £EcM £EcN §EcBSizeÒ §EcIndex ¦EcDistš ¨CSumAlgo ¨PartNums‘ ©PartETags‘ ©PartSizes‘Ò 'ªPartASizes‘Ò...

This will make `tags` be a list, although it doesn't declare the type of the elements of the list.

## List fields with type parameter { #list-fields-with-type-parameter }

But Python has a specific way to declare lists with internal types, or "type parameters":

### Import typing's `List` { #import-typings-list }

In Python 3.9 and above you can use the standard `list` to declare these type annotations as we'll see below. 💡

pkg io/fs, method (FileMode) Type() FileMode
pkg io/fs, type DirEntry interface { Info, IsDir, Name, Type }
pkg io/fs, type DirEntry interface, Info() (FileInfo, error)
pkg io/fs, type DirEntry interface, IsDir() bool
pkg io/fs, type DirEntry interface, Name() string
pkg io/fs, type DirEntry interface, Type() FileMode
pkg io/fs, type FS interface { Open }
pkg io/fs, type FS interface, Open(string) (File, error)

import (
	"fmt"
	"sort"
	"strconv"
	"strings"
)

type Index struct {
	Name    string
	Class   string // UNIQUE | FULLTEXT | SPATIAL
	Type    string // btree, hash, gist, spgist, gin, and brin
	Where   string
	Comment string
	Option  string        // WITH PARSER parser_name
	Fields  []IndexOption // Note: IndexOption's Field maybe the same
}

type IndexOption struct {
	*Field
	Expression string