Problème de tri tableau à 2 dimensions

Bonjour à tous,

j'ai un soucis, je n'arrive pas à comprendre le tri du module operateur :
Code:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 from operator import itemgetter # Initialisation du tableau BasesX de 21 colonnes et 20 lignes # BasesX = [[0 for i in range(21)] for j in range(20)] BasesX = [[0] * 21 for _ in range(20)] for i in range(0,20): BasesX[i][0] = i + 1 BasesX[i][1] = i + 1 BasesX[i][2] = i + 1 BasesX[i][3] = i + 1 BasesX[i][4] = i + 1 for i in range(0,20): BasesX[i][5] = 20 - i BasesX[i][6] = 20 - i BasesX[i][7] = 20 - i BasesX[i][8] = 20 - i BasesX[i][9] = 20 - i for i in range(0,20): print(BasesX[i]) sorted(BasesX, key=itemgetter(0), reverse=True) print(" ") for i in range(0,20): print(BasesX[i]) sorted(BasesX, key=itemgetter(5), reverse=True) print(" ") for i in range(0,20): print(BasesX[i])
avec ce code, ça ne tri rien ! ci-dessous le résultat :

[1, 1, 1, 1, 1, 20, 20, 20, 20, 20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[2, 2, 2, 2, 2, 19, 19, 19, 19, 19, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[3, 3, 3, 3, 3, 18, 18, 18, 18, 18, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[4, 4, 4, 4, 4, 17, 17, 17, 17, 17, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[5, 5, 5, 5, 5, 16, 16, 16, 16, 16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[6, 6, 6, 6, 6, 15, 15, 15, 15, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[7, 7, 7, 7, 7, 14, 14, 14, 14, 14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[8, 8, 8, 8, 8, 13, 13, 13, 13, 13, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[9, 9, 9, 9, 9, 12, 12, 12, 12, 12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[11, 11, 11, 11, 11, 10, 10, 10, 10, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[12, 12, 12, 12, 12, 9, 9, 9, 9, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[13, 13, 13, 13, 13, 8, 8, 8, 8, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[14, 14, 14, 14, 14, 7, 7, 7, 7, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[15, 15, 15, 15, 15, 6, 6, 6, 6, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[16, 16, 16, 16, 16, 5, 5, 5, 5, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[17, 17, 17, 17, 17, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[18, 18, 18, 18, 18, 3, 3, 3, 3, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[19, 19, 19, 19, 19, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[20, 20, 20, 20, 20, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

[1, 1, 1, 1, 1, 20, 20, 20, 20, 20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[2, 2, 2, 2, 2, 19, 19, 19, 19, 19, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[3, 3, 3, 3, 3, 18, 18, 18, 18, 18, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[4, 4, 4, 4, 4, 17, 17, 17, 17, 17, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[5, 5, 5, 5, 5, 16, 16, 16, 16, 16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[6, 6, 6, 6, 6, 15, 15, 15, 15, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[7, 7, 7, 7, 7, 14, 14, 14, 14, 14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[8, 8, 8, 8, 8, 13, 13, 13, 13, 13, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[9, 9, 9, 9, 9, 12, 12, 12, 12, 12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[11, 11, 11, 11, 11, 10, 10, 10, 10, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[12, 12, 12, 12, 12, 9, 9, 9, 9, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[13, 13, 13, 13, 13, 8, 8, 8, 8, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[14, 14, 14, 14, 14, 7, 7, 7, 7, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[15, 15, 15, 15, 15, 6, 6, 6, 6, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[16, 16, 16, 16, 16, 5, 5, 5, 5, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[17, 17, 17, 17, 17, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[18, 18, 18, 18, 18, 3, 3, 3, 3, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[19, 19, 19, 19, 19, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[20, 20, 20, 20, 20, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

[1, 1, 1, 1, 1, 20, 20, 20, 20, 20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[2, 2, 2, 2, 2, 19, 19, 19, 19, 19, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[3, 3, 3, 3, 3, 18, 18, 18, 18, 18, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[4, 4, 4, 4, 4, 17, 17, 17, 17, 17, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[5, 5, 5, 5, 5, 16, 16, 16, 16, 16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[6, 6, 6, 6, 6, 15, 15, 15, 15, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[7, 7, 7, 7, 7, 14, 14, 14, 14, 14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[8, 8, 8, 8, 8, 13, 13, 13, 13, 13, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[9, 9, 9, 9, 9, 12, 12, 12, 12, 12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[11, 11, 11, 11, 11, 10, 10, 10, 10, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[12, 12, 12, 12, 12, 9, 9, 9, 9, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[13, 13, 13, 13, 13, 8, 8, 8, 8, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[14, 14, 14, 14, 14, 7, 7, 7, 7, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[15, 15, 15, 15, 15, 6, 6, 6, 6, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[16, 16, 16, 16, 16, 5, 5, 5, 5, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[17, 17, 17, 17, 17, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[18, 18, 18, 18, 18, 3, 3, 3, 3, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[19, 19, 19, 19, 19, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[20, 20, 20, 20, 20, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

merci de votre aide.
Tchicken

Code:

sorted(X)

retourne une liste trié sans modifié X.

Code:

X.sort()

trie X et le modifie sur place.

Donc si vous écrivez juste

Code:

sorted(X)

il ne se passe rien. Soit il faut récupérer le résultat

Code:

Y=sorted(X)

et regarder Y, soit utiliser

Code:

X.sort()

Citation:

Envoyé par Tchicken

Bonjour à tous,

Bonjour à toi...
Citation:
Envoyé par Tchicken
j'ai un soucis, je n'arrive pas à comprendre le tri du module operateur :
Code:

1 2 3 4 5 6 7 for i in range(0,20): print(BasesX[i]) sorted(BasesX, key=itemgetter(0), reverse=True) print(" ") for i in range(0,20): print(BasesX[i]) sorted(BasesX, key=itemgetter(5), reverse=True)
avec ce code, ça ne trie rien !
Sisi (impératrice), sorted() trie parfaitement. Encore faut-il que tu récupères le truc trié qu'elle te renvoie...

Quand tu as un tableau à trier (ex tab=range(20, 0, -1)), et que tu veux trier le tableau, t'as deux possibilités
soit tu invoques la méthode sort() sur le tableau (ex tab.sort())=> il sera alors modifié et trié "sur place"
soit tu invoques la fonction globale sorted() à laquelle tu passes le tableau à trier (ex sorted(tab))=> la fonction retourne un nouveau tableau (qu'il faut alors récupérer) sans toucher au tableau d'origine