Bayesian Optimization XGBoost 적용 실행시 오류

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StopIteration                             Traceback (most recent call last)
File /usr/local/lib/python3.9/site-packages/bayes_opt/bayesian_optimization.py:179, in BayesianOptimization.maximize(self, init_points, n_iter, acq, kappa, kappa_decay, kappa_decay_delay, xi, **gp_params)
    178 try:
--> 179     x_probe = next(self._queue)
    180 except StopIteration:

File /usr/local/lib/python3.9/site-packages/bayes_opt/bayesian_optimization.py:25, in Queue.__next__(self)
     24 if self.empty:
---> 25     raise StopIteration("Queue is empty, no more objects to retrieve.")
     26 obj = self._queue[0]

StopIteration: Queue is empty, no more objects to retrieve.

During handling of the above exception, another exception occurred:

TypeError                                 Traceback (most recent call last)
Input In [22], in <module>
     36 optimizer = BayesianOptimization( f=xgboost_hyper_param, pbounds=pbounds, random_state=1)
     37 # init_points: 초기 랜덤 포인트 갯수
     38 # acq='ei': Expected Improvement 
     39 # xi=0.01: exploration(불확실성이 가장 높은 점 근처에 최적값이 존재할 것이라는 가정으로 계산된 값) 강도 (보통 0.01) 
---> 40 optimizer.maximize(init_points=10, n_iter=100, acq='ei', xi=0.01)

File /usr/local/lib/python3.9/site-packages/bayes_opt/bayesian_optimization.py:182, in BayesianOptimization.maximize(self, init_points, n_iter, acq, kappa, kappa_decay, kappa_decay_delay, xi, **gp_params)
    180 except StopIteration:
    181     util.update_params()
--> 182     x_probe = self.suggest(util)
    183     iteration += 1
    185 self.probe(x_probe, lazy=False)

File /usr/local/lib/python3.9/site-packages/bayes_opt/bayesian_optimization.py:131, in BayesianOptimization.suggest(self, utility_function)
    128     self._gp.fit(self._space.params, self._space.target)
    130 # Finding argmax of the acquisition function.
--> 131 suggestion = acq_max(
    132     ac=utility_function.utility,
    133     gp=self._gp,
    134     y_max=self._space.target.max(),
    135     bounds=self._space.bounds,
    136     random_state=self._random_state
    137 )
    139 return self._space.array_to_params(suggestion)

File /usr/local/lib/python3.9/site-packages/bayes_opt/util.py:65, in acq_max(ac, gp, y_max, bounds, random_state, n_warmup, n_iter)
     62     continue
     64 # Store it if better than previous minimum(maximum).
---> 65 if max_acq is None or -res.fun[0] >= max_acq:
     66     x_max = res.x
     67     max_acq = -res.fun[0]

TypeError: 'float' object is not subscriptable