Python 객체와 책임 분리

1class Member:2    def __init__(self, member_id, name):3        if not isinstance(member_id, int) or isinstance(member_id, bool) or member_id <= 0:4            raise ValueError("ID는 양의 정수여야 합니다.")5        self.member_id = member_id6        self.rename(name)7
8    def rename(self, name):9        if not isinstance(name, str) or not name.strip():10            raise ValueError("이름은 비울 수 없습니다.")11        self._name = name.strip()12
13    @property14    def name(self):15        return self._name16
17    def label(self):18        return f"{self.member_id}: {self.name}"19
20
21class Mentor(Member):22    def __init__(self, member_id, name, specialty):23        super().__init__(member_id, name)24        self.specialty = specialty25
26    def label(self):27        return f"{super().label()} / 멘토({self.specialty})"28
29
30if __name__ == "__main__":31    roster = [Member(1, "가람"), Mentor(2, "나래", "Python")]32    for member in roster:33        print(member.label())

1# 반례: 두 객체가 같은 목록을 공유합니다.2class BadTeam:3    members = []4
5# 수정: 팀을 만들 때마다 새 목록을 생성합니다.6class Team:7    def __init__(self):8        self.members = []

1import unittest2from members import Member, Mentor3
4class MemberTests(unittest.TestCase):5    def test_rename_keeps_valid_name_on_failure(self):6        member = Member(1, "가람")7        with self.assertRaises(ValueError):8            member.rename(" ")9        self.assertEqual(member.name, "가람")10
11    def test_instances_are_independent(self):12        first, second = Member(1, "가람"), Member(2, "나래")13        first.rename("다온")14        self.assertEqual(second.name, "나래")15
16    def test_polymorphism(self):17        member = Mentor(3, "라온", "Django")18        self.assertIsInstance(member, Member)19        self.assertIn("멘토", member.label())