---
id: python-if-statement
title: "Python If Statement"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["Python Conditions", "파이썬 조건문"]
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", "if", "conditions"]
raw_sources: ["https://www.w3schools.com/python/python_conditions.asp"]
applied_in: []
github_commit: ""
---

# [[Python If Statement]]

## 🎯 한 줄 통찰 (One-line insight)
An if statement runs its indented block only when its condition evaluates True — and a bare boolean variable (or almost any non-empty/non-zero value) can serve as the condition directly, without an explicit comparison. [S1]

## 🧠 핵심 개념 (Core concepts)
- **Standard comparisons** — `==`, `!=`, `<`, `<=`, `>`, `>=`. [S1]
- **`if` keyword** — evaluates a condition; executes the indented block if True, skips it if False. [S1]
- **Indentation-defined scope** — same as elsewhere in Python; missing/inconsistent indentation raises an error. [S1]
- **Multiple statements in one block** — all must share the same indentation level. [S1]
- **Boolean variables used directly** — `if is_logged_in:` needs no explicit `== True`. [S1]
- **Truthy/falsy in conditions** — 0, `""`, `None`, and empty collections are False; everything else (including negative numbers and non-empty strings like `"False"`) is True. [S1]

## 📖 세부 내용 (Details)
- Basic if: `a = 33; b = 200; if b > a: print("b is greater than a")`. [S1]
- Multi-statement block: `if age >= 18: print("You are an adult"); print("You can vote"); print("You have full legal rights")` (all same indentation). [S1]
- Boolean variable directly: `is_logged_in = True; if is_logged_in: print("Welcome back!")`. [S1]

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

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — Python Booleans 챕터에서 이미 다룬 truthy/falsy 평가 규칙이 여기서 if 조건 평가로 직접 적용된다. [S1]

## 💻 코드 패턴 (Code patterns)
Boolean variable used directly as a condition (Python):
```python
is_logged_in = True
if is_logged_in:
    print("Welcome back!")
```

## ✅ 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 Booleans]], [[Python Elif]], [[Python Else]], [[Python Operators Comparison]]
- **참조 맥락:** 조건문 전체의 진입점 — Elif/Else 챕터로 확장된다.

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

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