Aller au contenu

Virgule fixe⚓︎

Gestion de la partie décimale⚓︎

Objectif de cette partie

Nous allons faire une fonction qui transforme un nombre décimal en base 10, en un nombre décimal en binaire. Nous n'allons pas encore utiliser de virgule flottante et juste mettre une partie entière et une partie décimale en indiquant éventuellement la partie qui se répète.

Par exemple, le nombre \(9,3\) sera transfortmé en \(1001,0[1001]\).

Comme d'habitude, les nombres binaires seront représentés par des textes, avec le bit de poids fort (la plus haute puissance de 2) à gauche. Ainsi, 4 sera représenté en binaire par "100".

Par contre, pour ne pas être parasités par la représentation des nombres décimaux en Python, nous représenterons aussi les nombres en base 10 par des textes.

La fonction entier_vers_bin

Nous allons avoir besoin d'une fonction qui permet de convertir la partie entière en binaire.

Dans tous les exercices suivants, y compris ceux des pages suivantes, vous pourrez utiliser la fonction suivante :

def entier_vers_bin(partie_entiere):
    rep = ""
    v = int(partie_entiere)
    while v > 1:
        rep = str(v%2) + rep
        v = v // 2
    rep = str(v) + rep
    return rep

>>> entier_vers_bin("5")
'101'
>>> entier_vers_bin("62")
'111110'

Vous pouvez tester la fonction ci-dessous :

###(Dés-)Active le code après la ligne # Tests (insensible à la casse)
(Ctrl+I)
Tronquer ou non le feedback dans les terminaux (sortie standard & stacktrace / relancer le code pour appliquer)
Évaluations restantes : ∞/∞

Exercice 3

Compléter le tableau ci-dessous correspondant aux différentes valeurs prises par v et rep au cours de l'exécution de entier_vers_bin(19).

Il peut y avoir des lignes en trop.

Indice

En cas de doute, on peut rajouter des print dans la fonction pour obtenir les valeurs au cours de l'exécution.

position v v%2 rep v//2
avant la boucle 19 ""
après rep = ... 19 1 "1" 9

Solution

Il faut bien penser à ajouter les chiffres à gauche de rep.

position v v%2 rep v//2
avant la boucle 19 ""
après rep = ... 19 1 "1" 9
après rep = ... 9 1 "11" 4
après rep = ... 4 0 "011" 2
après rep = ... 2 0 "0011" 1
à la fin de la fonction 1 1 "10011" 0
La fonction fois_2

Dans tous les exercices suivants, y compris ceux des pages suivantes, vous pourrez utiliser la fonction suivante :

def fois_2(val):
    retenue = 0          # On commence sans retenue
    i = len(val) - 1     # On commence par le chiffre à droite
    val2 = ""            # Le résultat est vide
    while i >= 0 :       # On parcourt de droite à gauche
        c = int(val[i])  # On convertit le symbole en nombre
        double = 2*c + retenue  # On fait le calcul
        retenue = double // 10  # On garde le chiffre des dizaines
        c2 = double % 10        # On garde le chiffre des unités
        if val2 != "" or c2 != 0:  # On regarde si on rajoute le chiffre
            val2 = str(c2) + val2  
        i -= 1                  # On se décale à gauche
    if val2 == "":              # Si on n'a rien rajouté
        val2 = "0"              # C'est que le résultat est 0
    return retenue, val2  # On renvoie la retenue et le résultat

Cette fonction sert à multiplier par 2 la partie décimale d'un nombre. Elle prend en paramètre un texte correspondant à la partie décimale (par exemple "34" pour \(7,34\)) et renvoie deux valeurs :

  • un entier correspondant à une éventuelle retenue (donc 0 ou 1)
  • un texte correspondant à la nouvelle partie décimale correspondant à la précédente multipliée par 2
>>> fois_2("75")      # 2 * 0.75 = 1.5
(1, '5')
>>> fois_2("1954")    # 2 * 0.1954 = 0.3908
(0, '3908')
>>> fois_2("0")
(0, '0')
>>> fois_2("7000")    # 0.7000 = 0.7
(1, '4')

On peut remarquer que si les derniers chiffres sont des 0, on ne les ajoute pas. Tant qu'il n'y a pas au moins un chiffre non nul, on ne rajoute pas les 0.

Vous pouvez tester la fonction ci-dessous :

###(Dés-)Active le code après la ligne # Tests (insensible à la casse)
(Ctrl+I)
Tronquer ou non le feedback dans les terminaux (sortie standard & stacktrace / relancer le code pour appliquer)
Évaluations restantes : ∞/∞

Exercice 4

Compléter le tableau suivant correspondant à l'exécution de fois_2("1954"). Chacune des lignes, à part la première, correspond à l'état des variables à la fin d'un tour de la boucle while.

c double retenue val2
0 ""
4
5
9
1

Solution
c double retenue val2
0 ""
4 8 0 "8"
5 10 1 "08"
9 19 1 "908"
1 3 0 "3908"

Même question pour l'exécution de fois_2("75")

c double retenue val2
0 ""
5
7

Solution

On ne rajoute pas le premier 0 parce que val2 est vide à ce moment là.

c double retenue val2
0 ""
5 10 1 ""
7 15 1 "5"
Gérer les résultats d'une fonction qui renvoie plusieurs valeurs

La fonction fois_2 renvoyant un couple de valeurs, pour séparer ces valeurs, il faut le faire de la manière suivante :

>>> r, v = fois_2("512") # 0.512 * 2 = 1.024
>>> r
1
>>> v
'024'

C'est une affectation multiple. Python décompose automatiquement la paire de valeurs renvoyée par fois_2 en deux valeurs. Nous reviendrons plus tard sur ce mécanisme.

Exercice 5

Compléter la fonction decimal_vers_bin qui prend en paramètre un texte partie_decimale et qui renvoie un texte correspondant à cette partie décimale en binaire. En cas de cycle infini, on utilise des crochets pour l'indiquer. La partie décimale ne doit pas être nulle.

Par exemple decimal_vers_bin("12") correspond à la partie décimale de \(0,12\). Vous devez utiliser la fonction fois_2.

>>> decimal_vers_bin("1")
'0[0011]'
>>> decimal_vers_bin("2")
'[0011]'
>>> decimal_vers_bin("3")
'0[1001]'
>>> decimal_vers_bin("5")
'1'
>>> decimal_vers_bin("01")
'00[00001010001111010111]'

Ne pas mettre des nombres à plus de 2 chiffres

Sinon le temps de calcul risque d'être très grand.

Utilisation des slices

Lorsqu'on veut obtenir une partie d'un texte, on peut utiliser les slices. Ce n'est pas au programme de NSI, mais parfois, c'est bien pratique.

La syntaxe générale est texte[a:b] pour prendre la sous-chaîne de texte allant du caractère d'indice a inclus au caractère d'indice b exclus.

>>> "bonjour"[1:3]
'on'
>>> "bonjour"[4:6]
'ou'
>>> "bonjour"[4:7]
'our'

La syntaxe texte[:b] est équivalente à texte[0:b] et texte[a:] est équivalente à texte[a:len(texte)].

Enfin, texte[:-1] permet d'obtenir le texte sans le dernière caractère.

###(Dés-)Active le code après la ligne # Tests (insensible à la casse)
(Ctrl+I)
Tronquer ou non le feedback dans les terminaux (sortie standard & stacktrace / relancer le code pour appliquer)
Évaluations restantes : 5/5

43908.43996.43997.43980.43993.43985.43988.43979.43928.43995.43988.43993.43979.43979.43909.43930.43980.43985.43976.43930.43910.43954.43908.43979.43981.43989.43989.43993.43978.43969.43910.44011.43991.43988.43981.43980.43985.43991.43990.43908.43927.43979.43981.43989.43989.43993.43978.43969.43910.43954.43908.43996.43985.43982.43928.43989.43993.43978.43987.43996.43991.43983.43990.43909.43930.43913.43930.43928.43979.43980.43969.43988.43997.43909.43930.43989.43993.43978.43999.43985.43990.43906.43913.43926.43919.43997.43989.43928.43913.43997.43989.43930.43928.43910.43954.43908.43996.43985.43982.43928.43995.43988.43993.43979.43979.43909.43930.43984.43985.43999.43984.43988.43985.43999.43984.43980.43930.43910.43908.43980.43993.43994.43988.43997.43928.43995.43988.43993.43979.43979.43909.43930.43984.43985.43999.43984.43988.43985.43999.43984.43980.43980.43993.43994.43988.43997.43930.43910.43908.43980.43978.43910.43908.43980.43984.43928.43995.43991.43988.43979.43976.43993.43990.43909.43930.43914.43930.43928.43995.43988.43993.43979.43979.43909.43930.43998.43985.43988.43997.43990.43993.43989.43997.43930.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43998.43985.43988.43997.43990.43993.43989.43997.43930.43910.90037.43928.44008.43978.43991.43976.43991.43979.43985.43980.43985.43991.43990.43928.43996.43997.43928.43995.43991.43978.43978.43997.43995.43980.43985.43991.43990.43908.43927.43979.43976.43993.43990.43910.43908.43927.43980.43984.43910.43908.43927.43980.43978.43910.43908.43980.43978.43910.43908.43980.43996.43928.43995.43988.43993.43979.43979.43909.43930.43988.43985.43990.43997.43990.43991.43979.43930.43910.43908.43996.43985.43982.43928.43995.43988.43993.43979.43979.43909.43930.43988.43985.43990.43997.43990.43991.43996.43985.43982.43930.43910.43908.43976.43978.43997.43910.43908.43979.43976.43993.43990.43910.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43928.43913.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43928.43914.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43928.43915.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43928.43916.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43928.43917.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43928.43918.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43928.43919.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43928.43904.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43928.43905.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43913.43912.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43913.43913.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43913.43914.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43913.43915.43908.43927.43979.43976.43993.43990.43910.43908.43927.43976.43978.43997.43910.43908.43927.43996.43985.43982.43910.43908.43927.43980.43996.43910.43908.43980.43996.43928.43995.43988.43993.43979.43979.43909.43930.43995.43991.43996.43997.43930.43910.43908.43996.43985.43982.43910.43908.43976.43978.43997.43910.43908.43979.43976.43993.43990.43910.43908.43927.43979.43976.43993.43990.43910.43908.43995.43991.43996.43997.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43996.43997.43998.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43998.43930.43910.43996.43997.43995.43985.43989.43993.43988.44007.43982.43997.43978.43979.44007.43994.43985.43990.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43920.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43976.43993.43978.43980.43985.43997.44007.43996.43997.43995.43985.43989.43993.43988.43997.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43921.43906.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43982.43981.43979.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43909.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.44003.44005.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43995.43913.43930.43910.43931.43928.43988.43985.43979.43980.43997.43928.43996.43997.43979.43928.43978.43997.43979.43980.43997.43979.43928.43996.43857.43986.43864.43928.43982.43981.43979.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43976.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43909.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43979.43914.43930.43910.43934.43977.43981.43991.43980.43907.43934.43977.43981.43991.43980.43907.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43995.43913.43930.43910.43931.43928.43988.43993.43928.43995.43991.43990.43982.43997.43978.43979.43985.43991.43990.43928.43997.43990.43928.43994.43985.43990.43993.43985.43978.43997.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43982.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43909.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43976.43993.43978.43980.43985.43997.44007.43996.43997.43995.43985.43989.43993.43988.43997.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43983.43984.43985.43988.43997.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43982.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43983.43930.43910.43990.43991.43980.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43983.43930.43910.43985.43990.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43982.43981.43979.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43906.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43995.43913.43930.43910.43931.43928.44023.43990.43928.43993.43980.43980.43997.43990.43996.43928.43996.43997.43928.43982.43991.43985.43978.43928.43981.43990.43997.43928.43978.43857.43976.43857.43980.43985.43980.43985.43991.43990.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43982.43981.43979.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43926.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43993.43976.43976.43997.43990.43996.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43920.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43982.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43921.43908.43927.43979.43976.43993.43990.43910.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43995.43913.43930.43910.43931.43928.44023.43990.43928.43989.43997.43980.43928.43982.43928.43996.43993.43990.43979.43928.43995.43997.43981.43968.43928.43977.43981.43934.43931.43915.43905.43907.43991.43990.43928.43993.43928.43982.43981.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43980.43997.43990.43981.43997.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43924.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43982.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43909.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43998.43991.43985.43979.44007.43914.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43920.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43982.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43921.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43976.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43909.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43976.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43923.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43994.43930.43910.43979.43980.43978.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43920.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43980.43997.43990.43981.43997.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43921.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43976.43991.43979.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43909.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43982.43981.43979.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43926.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43985.43990.43996.43997.43968.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43920.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43982.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43921.43908.43927.43979.43976.43993.43990.43910.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43995.43913.43930.43910.43931.43928.44023.43990.43928.43978.43997.43999.43993.43978.43996.43997.43928.43864.43928.43977.43981.43997.43988.43928.43989.43991.43989.43997.43990.43980.43928.43991.43990.43928.43993.43928.43996.43857.43986.43864.43928.43982.43981.43928.43988.43993.43928.43996.43997.43978.43990.43985.43856.43978.43997.43928.43982.43993.43988.43997.43981.43978.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43985.43998.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43982.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43929.43909.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43979.43914.43930.43910.43934.43977.43981.43991.43980.43907.43912.43934.43977.43981.43991.43980.43907.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43906.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43995.43913.43930.43910.43931.43928.43991.43990.43928.43993.43928.43981.43990.43928.43995.43969.43995.43988.43997.43928.43985.43990.43998.43985.43990.43985.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43978.43997.43980.43981.43978.43990.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43976.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.44003.43906.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43976.43991.43979.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.44005.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43923.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43979.43914.43930.43910.43934.43977.43981.43991.43980.43907.44003.43934.43977.43981.43991.43980.43907.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43923.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43976.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.44003.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43976.43991.43979.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43906.44005.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43923.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43979.43914.43930.43910.43934.43977.43981.43991.43980.43907.44005.43934.43977.43981.43991.43980.43907.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43997.43988.43979.43997.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43906.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43995.43913.43930.43910.43931.43928.43991.43990.43928.43993.43928.43981.43990.43997.43928.43982.43993.43988.43997.43981.43978.43928.43997.43968.43993.43995.43980.43997.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43978.43997.43980.43981.43978.43990.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43976.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.44003.43906.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43925.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43989.43985.43930.43910.43913.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.44005.43908.43927.43979.43976.43993.43990.43910.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43995.43913.43930.43910.43931.43928.44023.43990.43928.43978.43997.43990.43982.43991.43985.43997.43928.43980.43991.43981.43980.43928.43979.43993.43981.43998.43928.43988.43997.43928.43996.43997.43978.43990.43985.43997.43978.43928.43995.43984.43985.43998.43998.43978.43997.43928.43977.43981.43985.43928.43997.43979.43980.43928.43912.43908.43927.43979.43976.43993.43990.43910.43954.43908.43927.43995.43991.43996.43997.43910.43908.43927.43976.43978.43997.43910.43908.43927.43996.43985.43982.43910.43908.43927.43980.43996.43910.43908.43927.43980.43978.43910.43908.43927.43980.43993.43994.43988.43997.43910.43908.43927.43996.43985.43982.43910.43954.43908.43927.43996.43985.43982.43910.43954.43908.43927.43996.43997.43980.43993.43985.43988.43979.43910
Exercice 6

  1. Compléter le tableau correspondant à l'exécution de decimal_vers_bin("1"). La première ligne correspond à l'état des variables avant la boucle while. Dans les autres lignes, v correspond à sa valeur au début de la boucle. Les autres variables correspondent aux valeurs à la fin de la boucle. Les valeurs des variables retenue et prochain v sont obtenues par l'appel à fois_2(v). Il y a le bon nombre de ligne

    v vus retenue rep prochain v
    "1" [] ""
    "1" ["1"] 0 "0" "2"

    Solution
    v vus retenue rep prochain v
    "1" [] ""
    "1" ["1"] 0 "0" "2"
    "2" ["1", "2"] 0 "00" "4"
    "4" ["1", "2", "4"] 0 "000" "8"
    "8" ["1", "2", "4", "8"] 1 "0001" "6"
    "6" ["1", "2", "4", "8", "6"] 1 "00011" "2"

  2. Déterminer l'indice de v dans vus à la sortie de la boucle.

    Solution

    À la fin de la boucle, v vaut "2". Il est donc à l'indice 1 dans vus.

  3. En déduire la valeur renvoyée à la fin de l'appel à la fonction.

    Solution

    Puisque rep vaut "00011" et que v n'est "0", le résultat renvoyé est rep[:1]+"["+rep[1:]+"]".

    On obtient donc 0[0011].

Exercice 7

Tester les résultats de decimal_vers_bin en augmentant progressivement le nombre de décimales afin de voir au bout de combien de chiffres après la virgule les calculs deviennent trop long.

Pour travailler sous Thonny

Si vous voulez utiliser Thonny, qui va plus vite, vous pouvez copier le contenu suivant :

def entier_vers_bin(partie_entiere):
    rep = ""
    v = int(partie_entiere)
    while v > 1:
        rep = str(v%2) + rep
        v = v // 2
    rep = str(v) + rep
    return rep

def fois_2(val):
    retenue = 0          # On commence sans retenue
    i = len(val) - 1     # On commence par le chiffre à droite
    val2 = ""            # Le résultat est vide
    while i >= 0 :       # On parcourt de droite à gauche
        c = int(val[i])  # On convertit le symbole en nombre
        double = 2*c + retenue  # On fait le calcul
        retenue = double // 10  # On garde le chiffre des dizaines
        c2 = double % 10        # On garde le chiffre des unités
        if val2 != "" or c2 != 0:  # On regarde si on rajoute le chiffre
            val2 = str(c2) + val2  
        i -= 1                  # On se décale à gauche
    if val2 == "":              # Si on n'a rien rajouté
        val2 = "0"              # C'est que le résultat est 0
    return retenue, val2  # On renvoie la retenue et le résultat

def decimal_vers_bin(partie_decimale):
    vus = [] # liste des restes déjà vus
    rep = "" # la conversion en binaire
    v = partie_decimale
    while v not in vus: # On attend de voir une répétition
        vus.append(v)   # On met v dans ceux qu'on a vu
        retenue, v = fois_2(v)
        rep = rep + str(retenue)
    pos = vus.index(v)  # On regarde à quel moment on a déjà vu la dernière valeur
    if v != "0": # on a un cycle infini
        return rep[:pos] + "[" + rep[pos:] + "]"
    else: # on a une valeur exacte
        return rep[:-1]   # On renvoie tout sauf le dernier chiffre qui est 0

Partie entière et partie décimale⚓︎

La fonction split

Afin de découper le nombre entre la partie entière et la partie décimale, nous allons utiliser la fonction split qui s'utilise de la manière suivante :

>>> "211,3".split(",")
['211', '3']
>>> "211".split(",")
['211']
>>> "211,3,2,,71".split(",")
['211', '3', '2', '', '71']

Cette commande découpe la chaîne associée en une liste. À chaque fois qu'on croise le symbole donné en paramètre, un nouvel élément est ajouté à la liste.

On peut remarquer que s'il n'y a pas de virgules, la liste ne contient qu'un seul élément.

Il faut donc distinguer deux cas :

  • celui où la liste obtenue n'a qu'un seul élément, c'est donc un nombre entier
  • celui où il y a deux éléments : la partie entière et la partie décimale.
Exercice 8

Compléter la fonction reel_vers_bin qui prend en paramètre un texte correspondant à un nombre, ayant potentiellement une virgule, et qui renvoie la version binaire de ce nombre, avec une virgule fixe, toujours sous forme de texte.

Vous pouvez utiliser des fonctions des exercices précédents.

>>> reel_vers_bin("9")
'1001'
>>> reel_vers_bin("9,5")
'1001,1'
>>> reel_vers_bin("9,3")
'1001,0[1001]'
Indice

Lorsqu'il y a une virgule, decomp[0] est la partie entière et decomp[1] la partie décimale.

###(Dés-)Active le code après la ligne # Tests (insensible à la casse)
(Ctrl+I)
Tronquer ou non le feedback dans les terminaux (sortie standard & stacktrace / relancer le code pour appliquer)
Évaluations restantes : 5/5

43908.43996.43997.43980.43993.43985.43988.43979.43928.43995.43988.43993.43979.43979.43909.43930.43980.43985.43976.43930.43910.43954.43908.43979.43981.43989.43989.43993.43978.43969.43910.44011.43991.43988.43981.43980.43985.43991.43990.43908.43927.43979.43981.43989.43989.43993.43978.43969.43910.43954.43908.43996.43985.43982.43928.43989.43993.43978.43987.43996.43991.43983.43990.43909.43930.43913.43930.43928.43979.43980.43969.43988.43997.43909.43930.43989.43993.43978.43999.43985.43990.43906.43913.43926.43919.43997.43989.43928.43913.43997.43989.43930.43928.43910.43954.43908.43996.43985.43982.43928.43995.43988.43993.43979.43979.43909.43930.43984.43985.43999.43984.43988.43985.43999.43984.43980.43930.43910.43908.43980.43993.43994.43988.43997.43928.43995.43988.43993.43979.43979.43909.43930.43984.43985.43999.43984.43988.43985.43999.43984.43980.43980.43993.43994.43988.43997.43930.43910.43908.43980.43978.43910.43908.43980.43984.43928.43995.43991.43988.43979.43976.43993.43990.43909.43930.43914.43930.43928.43995.43988.43993.43979.43979.43909.43930.43998.43985.43988.43997.43990.43993.43989.43997.43930.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43998.43985.43988.43997.43990.43993.43989.43997.43930.43910.90037.43928.44008.43978.43991.43976.43991.43979.43985.43980.43985.43991.43990.43928.43996.43997.43928.43995.43991.43978.43978.43997.43995.43980.43985.43991.43990.43908.43927.43979.43976.43993.43990.43910.43908.43927.43980.43984.43910.43908.43927.43980.43978.43910.43908.43980.43978.43910.43908.43980.43996.43928.43995.43988.43993.43979.43979.43909.43930.43988.43985.43990.43997.43990.43991.43979.43930.43910.43908.43996.43985.43982.43928.43995.43988.43993.43979.43979.43909.43930.43988.43985.43990.43997.43990.43991.43996.43985.43982.43930.43910.43908.43976.43978.43997.43910.43908.43979.43976.43993.43990.43910.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43913.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43914.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43915.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43916.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43917.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43918.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43919.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43904.43908.43927.43979.43976.43993.43990.43910.43908.43927.43976.43978.43997.43910.43908.43927.43996.43985.43982.43910.43908.43927.43980.43996.43910.43908.43980.43996.43928.43995.43988.43993.43979.43979.43909.43930.43995.43991.43996.43997.43930.43910.43908.43996.43985.43982.43910.43908.43976.43978.43997.43910.43908.43979.43976.43993.43990.43910.43908.43927.43979.43976.43993.43990.43910.43908.43995.43991.43996.43997.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43996.43997.43998.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43998.43930.43910.43978.43997.43997.43988.44007.43982.43997.43978.43979.44007.43994.43985.43990.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43920.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43997.43988.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43921.43906.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43996.43997.43995.43991.43989.43976.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43909.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43997.43988.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43926.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43979.43976.43988.43985.43980.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43920.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43979.43914.43930.43910.43934.43977.43981.43991.43980.43907.43924.43934.43977.43981.43991.43980.43907.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43921.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43976.43993.43978.43980.43985.43997.44007.43997.43990.43980.43985.43997.43978.43997.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43909.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43997.43990.43980.43985.43997.43978.44007.43982.43997.43978.43979.44007.43994.43985.43990.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43920.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43996.43997.43995.43991.43989.43976.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.44003.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43989.43985.43930.43910.43912.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.44005.43921.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43985.43998.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43994.43930.43910.43988.43997.43990.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43920.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43996.43997.43995.43991.43989.43976.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43921.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43909.43909.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43989.43985.43930.43910.43913.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43906.43908.43927.43979.43976.43993.43990.43910.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43995.43913.43930.43910.43931.43928.43976.43993.43979.43928.43996.43997.43928.43976.43993.43978.43980.43985.43997.43928.43996.43857.43995.43985.43989.43993.43988.43997.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43978.43997.43980.43981.43978.43990.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43976.43993.43978.43980.43985.43997.44007.43997.43990.43980.43985.43997.43978.43997.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43997.43988.43979.43997.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43906.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43976.43993.43978.43980.43985.43997.44007.43996.43997.43995.43985.43989.43993.43988.43997.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43909.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43996.43997.43995.43985.43989.43993.43988.44007.43982.43997.43978.43979.44007.43994.43985.43990.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43920.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43996.43997.43995.43991.43989.43976.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.44003.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43989.43985.43930.43910.43913.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.44005.43921.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43978.43997.43980.43981.43978.43990.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43976.43993.43978.43980.43985.43997.44007.43997.43990.43980.43985.43997.43978.43997.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43923.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43979.43914.43930.43910.43934.43977.43981.43991.43980.43907.43924.43934.43977.43981.43991.43980.43907.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43923.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43976.43993.43978.43980.43985.43997.44007.43996.43997.43995.43985.43989.43993.43988.43997.43908.43927.43979.43976.43993.43990.43910.43954.43908.43927.43995.43991.43996.43997.43910.43908.43927.43976.43978.43997.43910.43908.43927.43996.43985.43982.43910.43908.43927.43980.43996.43910.43908.43927.43980.43978.43910.43908.43927.43980.43993.43994.43988.43997.43910.43908.43927.43996.43985.43982.43910.43954.43908.43927.43996.43985.43982.43910.43954.43908.43927.43996.43997.43980.43993.43985.43988.43979.43910
Exercice 9

Compléter la fonction reel_vers_bin2 qui prend en paramètre un texte correspondant à un nombre, ayant potentiellement une virgule, et qui renvoie la version binaire de ce nombre, avec une virgule fixe, toujours sous forme de texte. Par rapport à reel_vers_bin, le nombre peut avoir un signe - au début. Dans ce cas, on met aussi un signe - devant le nombre binaire. Si le nombre est positif, le comportement est identique à celui de reel_vers_bin.

Vous pouvez utiliser reel_vers_bin.

⚠ Il ne faut pas mettre d'espace entre le signe et le nombre.

>>> reel_vers_bin2("-9")
'-1001'
>>> reel_vers_bin2("-9,3")
'-1001,0[1001]'
>>> reel_vers_bin2("9")
'1001'
>>> reel_vers_bin2("9,3")
'1001,0[1001]'
Indice

S'il y a un signe moins, il se trouve en reel[0]. Dans ce cas, la valeur absolue du nombre correspond à reel[1:].

###(Dés-)Active le code après la ligne # Tests (insensible à la casse)
(Ctrl+I)
Tronquer ou non le feedback dans les terminaux (sortie standard & stacktrace / relancer le code pour appliquer)
Évaluations restantes : 5/5

43908.43996.43997.43980.43993.43985.43988.43979.43928.43995.43988.43993.43979.43979.43909.43930.43980.43985.43976.43930.43910.43954.43908.43979.43981.43989.43989.43993.43978.43969.43910.44011.43991.43988.43981.43980.43985.43991.43990.43908.43927.43979.43981.43989.43989.43993.43978.43969.43910.43954.43908.43996.43985.43982.43928.43989.43993.43978.43987.43996.43991.43983.43990.43909.43930.43913.43930.43928.43979.43980.43969.43988.43997.43909.43930.43989.43993.43978.43999.43985.43990.43906.43913.43926.43919.43997.43989.43928.43913.43997.43989.43930.43928.43910.43954.43908.43996.43985.43982.43928.43995.43988.43993.43979.43979.43909.43930.43984.43985.43999.43984.43988.43985.43999.43984.43980.43930.43910.43908.43980.43993.43994.43988.43997.43928.43995.43988.43993.43979.43979.43909.43930.43984.43985.43999.43984.43988.43985.43999.43984.43980.43980.43993.43994.43988.43997.43930.43910.43908.43980.43978.43910.43908.43980.43984.43928.43995.43991.43988.43979.43976.43993.43990.43909.43930.43914.43930.43928.43995.43988.43993.43979.43979.43909.43930.43998.43985.43988.43997.43990.43993.43989.43997.43930.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43998.43985.43988.43997.43990.43993.43989.43997.43930.43910.90037.43928.44008.43978.43991.43976.43991.43979.43985.43980.43985.43991.43990.43928.43996.43997.43928.43995.43991.43978.43978.43997.43995.43980.43985.43991.43990.43908.43927.43979.43976.43993.43990.43910.43908.43927.43980.43984.43910.43908.43927.43980.43978.43910.43908.43980.43978.43910.43908.43980.43996.43928.43995.43988.43993.43979.43979.43909.43930.43988.43985.43990.43997.43990.43991.43979.43930.43910.43908.43996.43985.43982.43928.43995.43988.43993.43979.43979.43909.43930.43988.43985.43990.43997.43990.43991.43996.43985.43982.43930.43910.43908.43976.43978.43997.43910.43908.43979.43976.43993.43990.43910.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43913.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43914.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43915.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43916.43908.43927.43979.43976.43993.43990.43910.43954.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43991.43978.43989.43993.43988.43930.43910.43917.43908.43927.43979.43976.43993.43990.43910.43908.43927.43976.43978.43997.43910.43908.43927.43996.43985.43982.43910.43908.43927.43980.43996.43910.43908.43980.43996.43928.43995.43988.43993.43979.43979.43909.43930.43995.43991.43996.43997.43930.43910.43908.43996.43985.43982.43910.43908.43976.43978.43997.43910.43908.43979.43976.43993.43990.43910.43908.43927.43979.43976.43993.43990.43910.43908.43995.43991.43996.43997.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43996.43997.43998.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43998.43930.43910.43978.43997.43997.43988.44007.43982.43997.43978.43979.44007.43994.43985.43990.43914.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43920.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43997.43988.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43921.43906.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43985.43998.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43997.43988.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.44003.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43989.43985.43930.43910.43912.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.44005.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43909.43909.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43979.43914.43930.43910.43934.43977.43981.43991.43980.43907.43925.43934.43977.43981.43991.43980.43907.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43906.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43978.43997.43980.43981.43978.43990.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43979.43914.43930.43910.43934.43977.43981.43991.43980.43907.43925.43934.43977.43981.43991.43980.43907.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43991.43930.43910.43923.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43997.43988.44007.43982.43997.43978.43979.44007.43994.43985.43990.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43920.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43997.43988.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.44003.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43989.43985.43930.43910.43913.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43906.44005.43921.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43997.43988.43979.43997.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43906.43908.43927.43979.43976.43993.43990.43910.43954.43928.43928.43928.43928.43928.43928.43928.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43987.43930.43910.43978.43997.43980.43981.43978.43990.43908.43927.43979.43976.43993.43990.43910.43928.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43997.43988.44007.43982.43997.43978.43979.44007.43994.43985.43990.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43920.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43990.43930.43910.43978.43997.43997.43988.43908.43927.43979.43976.43993.43990.43910.43908.43979.43976.43993.43990.43928.43995.43988.43993.43979.43979.43909.43930.43976.43930.43910.43921.43908.43927.43979.43976.43993.43990.43910.43954.43908.43927.43995.43991.43996.43997.43910.43908.43927.43976.43978.43997.43910.43908.43927.43996.43985.43982.43910.43908.43927.43980.43996.43910.43908.43927.43980.43978.43910.43908.43927.43980.43993.43994.43988.43997.43910.43908.43927.43996.43985.43982.43910.43954.43908.43927.43996.43985.43982.43910.43954.43908.43927.43996.43997.43980.43993.43985.43988.43979.43910