---
id: python-polymorphism
title: "Python Polymorphism"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["method overriding", "파이썬 다형성"]
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", "polymorphism", "inheritance"]
raw_sources: ["https://www.w3schools.com/python/python_polymorphism.asp"]
applied_in: []
github_commit: ""
---

# [[Python Polymorphism]]

## 🎯 한 줄 통찰 (One-line insight)
Polymorphism lets one for-loop call `.move()` on Car, Boat, and Plane objects uniformly — and combined with inheritance, a child class can inherit a method wholesale (Car) or override it entirely (Boat, Plane) while still fitting the same interface. [S1]

## 🧠 핵심 개념 (Core concepts)
- **Polymorphism** — "many forms"; methods/functions/operators with the same name executable on many different objects/classes. [S1]
- **Function polymorphism** — a single function like `len()` behaves appropriately across different types (string length, tuple item count, dict key-value pair count). [S1]
- **Class polymorphism** — unrelated classes (Car, Boat, Plane) each define their own `move()`; calling `.move()` in a loop over mixed objects "just works" for each type. [S1]
- **Inheritance + polymorphism** — child classes of a common parent can either inherit the parent's method unchanged (Car) or override it with their own version (Boat, Plane). [S1]

## 🧩 추출된 패턴 (Extracted patterns)
- **Uniform iteration over mixed types** — `for x in (car1, boat1, plane1): x.move()` works regardless of each object's actual class, because polymorphism guarantees `.move()` exists on all of them with the same call signature. [S1]

## 📖 세부 내용 (Details)
- `len()` across types: `len("Hello World!")`, `len(("apple","banana","cherry"))`, `len({"brand":"Ford",...})` — same function, different behavior per type. [S1]
- Unrelated classes sharing a method name: `Car`, `Boat`, `Plane` each define `move()` independently. [S1]
- Inheritance-based polymorphism: `Vehicle` parent defines `move()`; `Car` inherits it unchanged (`pass`), `Boat`/`Plane` override it with their own version. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
소스에서 모순되는 정보는 발견되지 않음.

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — 공통 인터페이스를 가진 서로 다른 객체를 동일한 코드로 다뤄야 할 때(예: 도형 넓이 계산) 표준적으로 쓰인다. [S1]

## 💻 코드 패턴 (Code patterns)
Uniform call over heterogeneous objects (Python):
```python
class Vehicle:
    def move(self): print("Move!")
class Car(Vehicle): pass
class Boat(Vehicle):
    def move(self): print("Sail!")
class Plane(Vehicle):
    def move(self): print("Fly!")

for x in (Car("Ford","Mustang"), Boat("Ibiza","Touring 20"), Plane("Boeing","747")):
    x.move()
```

## ✅ 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 Inheritance]], [[Python Class Methods]]
- **참조 맥락:** 공통 인터페이스를 가진 이종 객체를 동일하게 다룰 때 사용 — Inheritance와 결합해 메서드 오버라이드로 확장.

## 📚 출처 (Sources)
- [S1] W3Schools — Python Polymorphism — https://www.w3schools.com/python/python_polymorphism.asp

## 📝 변경 이력 (Change history)
- 2026-07-04: Initial draft synthesized from the W3Schools "Python Polymorphism" page (Astra wiki-curation, P-Reinforce v3.1 format).