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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def unlock(arguments):
 """Unlock the database."""

    import redis
    u = coil.utils.ask("Redis URL", "redis://localhost:6379/0")
    db = redis.StrictRedis.from_url(u)
    db.set('site:lock', 0)
    print("Database unlocked.")
    return 0