Méthodologie de la Programmation
Notes de cours - Séance I

Typage Fort

# Erreur
score = 42
print("le score est " + score)

# Bonne chose à faire
str(score)
print("le score est " + str(score))

Typage Dynamique

a = 42
type(a)

a = "test"
type(a)

a = 42
type(a)

a = "test"
type(a)

def truc(a):
    return "42" + a

truc("truc") # marche
truc(42) # plante

Definir None

def func_none():
    pass

print(func_none())

Comparer == et is

list1 = []
list2 = []
list3 = list1

list1 == list2 # True
list1 is list2 #False
list1 is list3 #True
list3 = list3 + list2
list1 is list3 # False

Flottants

a = 13.51 # float
a = 13,51 # tuple

String

a = "bli"
b = 'bli'

a == b # True

"Je m'appelle Python"
"dites \"AAAAAAH\"."

'Je m\'appelle Python'
'dites "AAAAAAH".'

"cou" * 2 # vaut "coucou"
"MIT" + "SIC" # vaut "MITSIC"

Tuples

nom, age = "Bob", 24
age, nom = nom, age

def return_tuple(a, b):
    return b, a

c = return_tuple(42, 227)
type(c) # tuple

len(c) # 2

c[0] # 42
c[1] # 227

Dictionnaires

mdlp = {
    'niveau': 'L1',
    'semestre': 1,
    'enseignants': {
        'C': 'JP Palus',
        'B': 'Alice Millour',
        'C': 'Anna Pappa'
    }
}

mdlp['niveau'] # 'L1'
mdlp['enseignants']['C'] # 'JP Palus'

Itération sur les listes

lst = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

[n * 2 for n in lst] # multiplie par 2 chaque élément de n

[n * n for n in lst if (n % 2) == 0] # met au carré les élements pairs

Fonctions

# Déclaration
def fact(n): # factorielle
    result = 1
    while n > 1:
        result = n * result
        n = n - 1
    return result

# Appel
a = fact(5) # a = 120