---
id: python-class-init-method
title: "Python Class Init Method"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["__init__()", "constructor", "파이썬 초기화 메서드"]
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", "init", "constructor"]
raw_sources: ["https://www.w3schools.com/python/python_class_init.asp"]
applied_in: []
github_commit: ""
---

# [[Python Class Init Method]]

## 🎯 한 줄 통찰 (One-line insight)
`__init__()` runs automatically every time a class creates a new object, replacing the need to manually set properties one by one after instantiation. [S1]

## 🧠 핵심 개념 (Core concepts)
- **`__init__()`** — a built-in method automatically executed when a class is instantiated. [S1]
- **Purpose** — assigns values to object properties or performs setup operations. [S1]
- **Without `__init__()`** — properties must be set manually on each object after creation. [S1]
- **Default parameter values** — `def __init__(self, name, age=18):` — parameters can have defaults, same as regular functions. [S1]
- **Multiple parameters** — `__init__()` can take as many parameters as needed. [S1]

## 📖 세부 내용 (Details)
- Basic init: `class Person: def __init__(self, name, age): self.name = name; self.age = age; p1 = Person("Emil", 36)`. [S1]
- Manual setup without init: `class Person: pass; p1 = Person(); p1.name = "Tobias"; p1.age = 25`. [S1]
- Default value: `def __init__(self, name, age=18): ...; p1 = Person("Emil")` → age defaults to 18. [S1]
- Multiple parameters: `def __init__(self, name, age, city, country): ...`. [S1]

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

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — Inheritance 챕터에서 자식 클래스가 `__init__()`을 재정의하거나 `super().__init__()`으로 부모 초기화를 호출하는 패턴으로 확장된다. [S1]

## 💻 코드 패턴 (Code patterns)
Init with a default parameter value (Python):
```python
class Person:
    def __init__(self, name, age=18):
        self.name = name
        self.age = age

p1 = Person("Emil")       # age defaults to 18
p2 = Person("Tobias", 25)
```

## ✅ 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 Classes]], [[Python Class Self Parameter]], [[Python Inheritance]]
- **참조 맥락:** 객체 생성 시 자동 실행되는 초기화 메서드 — Inheritance에서 super().__init__()으로 재사용된다.

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

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