Les iterables de python3 101: Slides axées sur les itérables (list, tuple, dict, etc.) décrivant de bonnes pratiques pour développeurs python débutants
7. for loop
languages = [‘php’, ‘ruby’, ‘python’]
frameworks = [‘symfony’, ‘ruby on rails’, ‘django’]
for i in range(len(languages)):
print(languages[i] + ‘: ’ + frameworks[i])
8. for loop
languages = [‘php’, ‘ruby’, ‘python’]
frameworks = [‘symfony’, ‘ruby on rails’, ‘django’]
for i, language in enumerate(languages):
print(‘: ’.join([language, frameworks[i]]))
for language, framework in zip(languages, frameworks):
print(‘: ’.join([language, framework]))
10. Set
Sets acceptent les
opérations mathématiques:
● Union
● Intersection
● Difference
● Et d’autres opérations
plus chelou, mais ça fait
de jolies figures
12. mapping = dict() # ou {}
for language, framework in zip(languages, frameworks):
if not language in languages:
mapping[language] = []
mapping[language].append(framework)
dict
13. mapping = defaultdict(list)
for language, framework in zip(languages, frameworks):
mapping[language].append(framework)
mapping = {}
for l, framework in zip(languages, frameworks):
mapping.setdefault(l, []).append(framework)
dict
14. dict
mapping = {‘php’:[‘symfony’], ‘ruby’:[’ruby on rails’],
‘python’:[’django’]}
for language in mapping:
print(language)
for language, frameworks in mapping.items():
print(language, frameworks)
15. dict
mapping = {‘php’:[‘symfony’], ‘ruby’:[’ruby on rails’],
‘python’:[’django’]}
print(mapping[‘python’])
del mapping[‘python’]
print(mapping.get(‘python’, ‘flask’))
Mapping[‘python’] = ‘pyramid’
16. muabilité
# Les listes sont muables. Elles peuvent être mis à jour:
list1 = [1,]
list1.append(2)
list1 == [1, 2]
Et d’autres méthodes...
list2 = [1,]
list2.insert(0, 2)
list2 == [2, 1]
17. muabilité
# Cool mais...
list2 = list1
list1.append(3)
list2 == [1, 2, 3]
# list2 “pointe” vers list1.
# list1 et list2 sont la même
liste en fait...
21. Compréhension à la portée de tous!
list1 = [x for x in z if not x == ‘foo’]
gen = (x for x in z if not x == ‘foo’)
# Nope c’est pas un tuple! Mais un générateur.
set1 = {x for x in z if not x == ‘foo’}
dic1 = {x: x.bar for x in z if not x == ‘foo’}