تلاش مجدد با زمینه‌بان

from contextlib import contextmanager

attempts = {"n": 0}

@contextmanager
def connection():
    print("اتصال باز شد.")
    try:
        yield "conn"
    finally:
        print("اتصال بسته شد.")

def fragile_fetch():
    attempts["n"] += 1
    if attempts["n"] < 3:
        raise ConnectionError("قطعی موقت.")
    return "داده رسید!"

with connection():
    for i in range(3):
        try:
            print(fragile_fetch())
            break
        except ConnectionError as e:
            print(f"تلاش {i+1} ناموفق: {e}")