--- id: python-inheritance title: "Python Inheritance" category: "Programming_Language" status: "draft" verification_status: "conceptual" canonical_id: "" aliases: ["super()", "parent class", "child class", "파이썬 상속"] duplicate_of: "" source_trust_level: "B" confidence_score: 0.9 created_at: 2026-07-04 updated_at: 2026-07-04 review_reason: "" merge_history: [] tags: ["python", "programming", "w3schools", "inheritance", "super"] raw_sources: ["https://www.w3schools.com/python/python_inheritance.asp"] applied_in: [] github_commit: "" --- # [[Python Inheritance]] ## 🎯 한 줄 통찰 (One-line insight) Adding a child class's own `__init__()` silently OVERRIDES the parent's — inheritance of the parent's initialization is only restored by explicitly calling `Parent.__init__(self, ...)` or, more idiomatically, `super().__init__(...)`. [S1] ## 🧠 핵심 개념 (Core concepts) - **Parent (base) class** — the class being inherited from. [S1] - **Child (derived) class** — the class that inherits: `class Student(Person):`. [S1] - **`pass` for pure inheritance** — a child class with no additions just inherits everything as-is. [S1] - **Overriding `__init__()`** — adding `__init__()` to the child REMOVES the automatic inheritance of the parent's `__init__()`. [S1] - **Explicit parent call** — `Person.__init__(self, fname, lname)` restores the parent's initialization behavior. [S1] - **`super()`** — a cleaner way to call the parent's methods without naming the parent class explicitly. [S1] - **Adding new properties/methods** — the child class can extend beyond what it inherited (e.g. `graduationyear`, `welcome()`). [S1] - **Method overriding** — a child method with the same name as a parent method REPLACES the parent's version for that child. [S1] ## 🧩 추출된 패턴 (Extracted patterns) - **super() decouples child from parent's name** — using `super().__init__(...)` instead of `Person.__init__(self, ...)` means if the parent class is ever renamed, the child code doesn't need to change. [S1] ## 📖 세부 내용 (Details) - Pure inheritance: `class Student(Person): pass`. [S1] - Overridden init (loses parent init): `class Student(Person): def __init__(self, fname, lname): #...`. [S1] - Restored via explicit call: `class Student(Person): def __init__(self, fname, lname): Person.__init__(self, fname, lname)`. [S1] - Restored via super(): `class Student(Person): def __init__(self, fname, lname): super().__init__(fname, lname)`. [S1] - Extended with new property: `super().__init__(fname, lname); self.graduationyear = year`. [S1] - New method: `def welcome(self): print("Welcome", self.firstname, self.lastname, "to the class of", self.graduationyear)`. [S1] ## ⚖️ 모순 및 업데이트 (Contradictions & updates) 소스에서 모순되는 정보는 발견되지 않음. 자식 클래스의 __init__() 추가가 부모 초기화 상속을 깨뜨린다는 점이 명시적으로 경고됨. [S1] ## 🛠️ 적용 사례 (Applied in summary) 현재 발견된 실제 적용 사례가 없습니다 — Polymorphism 챕터에서 자식 클래스가 부모 메서드를 오버라이드하는 패턴이 확장된다. [S1] ## 💻 코드 패턴 (Code patterns) super() to extend the parent's init (Python): ```python class Student(Person): def __init__(self, fname, lname, year): super().__init__(fname, lname) self.graduationyear = year x = Student("Mike", "Olsen", 2019) ``` ## ✅ 검증 상태 및 신뢰도 - **상태:** draft - **검증 단계:** conceptual - **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body) - **신뢰 점수:** 0.90 - **중복 검사 결과:** 신규 생성 (New discovery) ## 🔗 지식 그래프 (Knowledge Graph) - **상위/루트:** [[Python Tutorial]] - **관련 개념:** [[Python Class Init Method]], [[Python Polymorphism]] - **참조 맥락:** 클래스 재사용의 핵심 메커니즘 — Polymorphism에서 메서드 오버라이드로 확장. ## 📚 출처 (Sources) - [S1] W3Schools — Python Inheritance — https://www.w3schools.com/python/python_inheritance.asp ## 📝 변경 이력 (Change history) - 2026-07-04: Initial draft synthesized from the W3Schools "Python Inheritance" page (Astra wiki-curation, P-Reinforce v3.1 format).