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contextlibの使い方

ipynbFile contextlib__contextlibの使い方.ipynb

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contextmanagerはデコレーターを with を使用して書けるようにできるしろもの

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from contextlib import contextmanager

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@contextmanager
def sample(*args,**kwargs):
    print('start')
    yield
    print('end')

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with sample() as f:
    print("hoge")

Success

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start
hoge
end

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@contextmanager
def _Stream(path, *args, **kwargs):
    if path == '-':
        yield sys.stdout
    else:
        with open(path, *args, **kwargs) as fp:
            yield fp

def _Print(stream, msg):
    print(msg, file=stream)

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# 指定パス以下にテキストを書き出す
with _Stream("D:/sample.txt",'w') as f:
    _Print(f,'sample')

Success

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hoge

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with _Stream("-") as f:
    _Print(f,"hoge")
    _Print(f,"Hello World!!")

Success

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hoge
Hello World!!

最終更新日: 2022-11-25 15:39:17