def worker_exploration(worker_index, num_workers):
    """
    Computes an exploration value for a worker
    Args:
        worker_index (int): This worker's integer index.
        num_workers (int): Total number of workers.
    Returns:
        float: Constant epsilon value to use.
    """
    exponent = (1.0 + worker_index / float(num_workers - 1) * 7)
    return 0.4 ** exponent