def sum_lifespans(agent_stats, skill_headers=None, n_policies=1, verbose=False, pop=None):
    lifespans = get_pop_stats(agent_stats['lifespans'], pop=pop)
    score = lifespans.mean()
    if verbose:
        print('Mean lifespan, pop {}: {}'.format(pop, score))
    return score
def sum_lifespans(agent_stats, skill_headers=None, n_policies=1, verbose=False, pop=None):
    lifespans = get_pop_stats(agent_stats['lifespans'], pop=pop)
    score = lifespans.mean()
    if verbose:
        print('Mean lifespan, pop {}: {}'.format(pop, score))
    return score