Prečítaj kód pozorne

from contextlib import ExitStack, contextmanager


@contextmanager
def res(name):
    print(f"open:{name}")
    try:
        yield name
    finally:
        print(f"close:{name}")


with ExitStack() as stack:
    a = stack.enter_context(res("A"))
    b = stack.enter_context(res("B"))
    c = stack.enter_context(res("C"))
    print(f"use:{a}{b}{c}")

print("done")

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