match와 case 기초

구조적 패턴 일치

기본 구문

command = 'start'

match command:
    case 'start':
        print('Starting up')
    case 'stop':
        print('Shutting down')

# prints: Starting up

리터럴과 일치시키기

code = 404

match code:
    case 200:
        print('OK')
    case 404:
        print('Not Found')
    case 500:
        print('Server Error')

와일드카드 _

code = 418

match code:
    case 200:
        print('OK')
    case _:
        print('Unknown status')

OR로 결합하기

code = 301

match code:
    case 200 | 201 | 204:
        print('Success')
    case 301 | 302:
        print('Redirect')
    case _:
        print('Other')

값 캡처하기

value = 42

match value:
    case 0:
        print('zero')
    case other:
        print('got', other)

순서가 중요합니다

x = 5

match x:
    case n:           # matches everything first!
        print('caught by capture')
    case 5:
        print('this never runs')

패턴 일치는 아무것도 반환하지 않음

day = 6
label = ''

match day:
    case 0 | 6:
        label = 'weekend'
    case _:
        label = 'weekday'

print(label)

None과 일치시키기

def describe(value):
    match value:
        case None:
            return 'nothing'
        case _:
            return 'something: ' + str(value)

print(describe(None))
print(describe(7))

실용적인 분배기

def handle(cmd):
    match cmd:
        case 'help':
            return 'Showing help'
        case 'quit' | 'exit':
            return 'Goodbye'
        case _:
            return 'Unknown command'

print(handle('exit'))
print(handle('foo'))

True, False, None과 일치시키기

def report(flag):
    match flag:
        case True:
            return 'enabled'
        case False:
            return 'disabled'
        case None:
            return 'unset'

print(report(True))
print(report(None))

빠른 확인

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