2nd/10_Wiki/Dev/Topic_Python/Python_Operators_Membership.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-operators-membership	Python Operators Membership	Programming_Language	draft	conceptual		in operator not in operator 파이썬 멤버십 연산자		B	0.9	2026-07-04	2026-07-04			python programming w3schools operators membership	https://www.w3schools.com/python/python_operators_membership.asp

Python Operators Membership

🎯 한 줄 통찰 (One-line insight)

in/not in test whether a value exists within any sequence — lists and strings alike — using identical syntax. [S1]

🧠 핵심 개념 (Core concepts)

• in — True if a specified value is present in the sequence. [S1]
• not in — True if a specified value is NOT present in the sequence. [S1]
• Works across sequence types — lists and strings both support membership testing. [S1]

📖 세부 내용 (Details)

• List membership: fruits = ["apple", "banana", "cherry"]; print("banana" in fruits). [S1]
• List non-membership: print("pineapple" not in fruits). [S1]
• String membership: text = "Hello World"; print("H" in text); print("hello" in text) # False, case-sensitive; print("z" not in text). [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

소스에서 모순되는 정보는 발견되지 않음.

🛠️ 적용 사례 (Applied in summary)

현재 발견된 실제 적용 사례가 없습니다 — 이미 Python Strings 챕터에서 문자열 대상 in이 선행 소개되었고, 여기서 리스트로 확장된다. [S1]

💻 코드 패턴 (Code patterns)

Membership test on a list (Python):

fruits = ["apple", "banana", "cherry"]
print("banana" in fruits)
print("pineapple" not in fruits)

✅ 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 Strings, Python Lists, Python If Else
• 참조 맥락: 시퀀스(리스트/문자열)에 값이 존재하는지 확인할 때 사용.

📚 출처 (Sources)

• [S1] W3Schools — Python Membership Operators — https://www.w3schools.com/python/python_operators_membership.asp

📝 변경 이력 (Change history)

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