2nd/10_Wiki/Topic_Programming/Topic_Python/Python_Nested_If.md

id, title, category, status, verification_status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, created_at, updated_at, review_reason, merge_history, tags, raw_sources, applied_in, github_commit

id	title	category	status	verification_status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	created_at	updated_at	review_reason	merge_history	tags	raw_sources	applied_in	github_commit
python-nested-if	Python Nested If	Programming_Language	draft	conceptual		Nested If Statements 파이썬 중첩 조건문		B	0.9	2026-07-04	2026-07-04			python programming w3schools if nested	https://www.w3schools.com/python/python_if_nested_if.asp

Python Nested If

🎯 한 줄 통찰 (One-line insight)

Nesting an if inside another if lets the inner condition depend on the outer one being true first, and it's interchangeable with and when both conditions are equally simple — nesting wins when the inner logic is genuinely conditional on the outer branch. [S1]

🧠 핵심 개념 (Core concepts)

• Nested if — an if statement inside another if statement; the inner one only runs when the outer condition is true. [S1]
• Multiple nesting levels — legal to any depth, but readability degrades quickly with too many levels. [S1]
• Nested if vs. and — if temperature > 20: if is_sunny: ... is equivalent to if temperature > 20 and is_sunny: ... when there's no independent action tied to just the outer condition. [S1]

🧩 추출된 패턴 (Extracted patterns)

• When to nest vs. combine with and — use nested if when the inner logic is complex or genuinely depends on the outer condition (e.g. different messages at each level); use and when both conditions are simple and equally weighted. [S1]

📖 세부 내용 (Details)

• Basic nesting: if x > 10: print("Above ten,"); if x > 20: print("and also above 20!") else: print("but not above 20."). [S1]
• Three-level nesting: score → attendance → submitted, each gating the next. [S1]
• Equivalent forms: if temperature > 20: if is_sunny: ... ≡ if temperature > 20 and is_sunny: .... [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

소스에서 모순되는 정보는 발견되지 않음.

🛠️ 적용 사례 (Applied in summary)

현재 발견된 실제 적용 사례가 없습니다 — 로그인 검증(username→password→is_active)처럼 단계적으로 좁혀지는 조건 체크에 전형적으로 쓰인다. [S1]

💻 코드 패턴 (Code patterns)

Nested if for step-wise validation (Python):

username = "Emil"
password = "python123"
is_active = True
if username:
    if password:
        if is_active:
            print("Login successful")
        else:
            print("Account is not active")
    else:
        print("Password required")
else:
    print("Username required")

✅ 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 If Statement, Python Operators Logical, Python Elif
• 참조 맥락: 단계적 조건 분기의 표준 패턴 — and 연산자와 상호 대체 가능한 경우가 많다.

📚 출처 (Sources)

• [S1] W3Schools — Python Nested If — https://www.w3schools.com/python/python_if_nested_if.asp

📝 변경 이력 (Change history)

• 2026-07-04: Initial draft synthesized from the W3Schools "Python Nested If" page (Astra wiki-curation, P-Reinforce v3.1 format).