README.md

from dataclasses import dataclass

@dataclass
class Student:
    lastname: str
    firstname: str
    age: int
students = [ Student("Cavat", "Joel", 40),
Student("Albuquerque", "Paul", 17), Student("Orestis", "Malaspinas", 32) ]

# impératif
res = []
for s in students:
    if s.age >= 18:
        res.append( s.lastname )

# déclaratif
res = [ s.lastname for s in students if s.age >= 18 ]