Scikit-optimize: AttributeError: 'str' object has no attribute 'decode'

[nunocesarsa]

Hey! having a wonky issue, can't seem to find any place to check what to do.

My Error:

Fitting 3 folds for each of 5 candidates, totalling 15 fits
joblib.externals.loky.process_executor._RemoteTraceback:
"""
Traceback (most recent call last):
File "C:\Optimization\OptimEnv\env369\lib\site-packages\joblib\externals\loky\process_executor.py", line 431, in _process_worker
r = call_item()
File "C:\Optimization\OptimEnv\env369\lib\site-packages\joblib\externals\loky\process_executor.py", line 285, in __call__
return self.fn(self.args, *self.kwargs)
File "C:\Optimization\OptimEnv\env369\lib\site-packages\joblib_parallel_backends.py", line 595, in __call__
return self.func(args, *kwargs)
File "C:\Optimization\OptimEnv\env369\lib\site-packages\joblib\parallel.py", line 263, in __call__
for func, args, kwargs in self.items]
File "C:\Optimization\OptimEnv\env369\lib\site-packages\joblib\parallel.py", line 263, in
for func, args, kwargs in self.items]
File "C:\Optimization\OptimEnv\env369\lib\site-packages\sklearn\model_selection_validation.py", line 531, in _fit_and_score
estimator.fit(X_train, y_train, *fit_params)
File "C:\Optimization\OptimEnv\env369\lib\site-packages\sklearn\pipeline.py", line 335, in fit
self._final_estimator.fit(Xt, y, *fit_params_last_step)
File "C:\Optimization\OptimEnv\env369\lib\site-packages\sklearn\gaussian_process_gpr.py", line 249, in fit
bounds))
File "C:\Optimization\OptimEnv\env369\lib\site-packages\sklearn\gaussian_process_gpr.py", line 504, in _constrained_optimization
_check_optimize_result("lbfgs", opt_res)
File "C:\Optimization\OptimEnv\env369\lib\site-packages\sklearn\utils\optimize.py", line 243, in _check_optimize_result
).format(solver, result.status, result.message.decode("latin1"))
AttributeError: 'str' object has no attribute 'decode'
"""

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "Script_v01.py", line 261, in
gpr_BCV.fit(X,y)
File "C:\Optimization\OptimEnv\env369\lib\site-packages\skopt\searchcv.py", line 694, in fit
groups=groups, n_points=n_points_adjusted
File "C:\Optimization\OptimEnv\env369\lib\site-packages\skopt\searchcv.py", line 579, in _step
self._fit(X, y, groups, params_dict)
File "C:\Optimization\OptimEnv\env369\lib\site-packages\skopt\searchcv.py", line 423, in _fit
for parameters in parameter_iterable
File "C:\Optimization\OptimEnv\env369\lib\site-packages\joblib\parallel.py", line 1054, in __call__
self.retrieve()
File "C:\Optimization\OptimEnv\env369\lib\site-packages\joblib\parallel.py", line 933, in retrieve
self._output.extend(job.get(timeout=self.timeout))
File "C:\Optimization\OptimEnv\env369\lib\site-packages\joblib_parallel_backends.py", line 542, in wrap_future_result
return future.result(timeout=timeout)
File "C:\Users\Nuno\AppData\Local\Programs\Python\Python37\lib\concurrent\futures_base.py", line 428, in result
return self.__get_result()
File "C:\Users\Nuno\AppData\Local\Programs\Python\Python37\lib\concurrent\futures_base.py", line 384, in __get_result
raise self._exception
AttributeError: 'str' object has no attribute 'decode'

---

My call:
`param_RBF = {
'model':[GaussianProcessRegressor(kernel=1RBF(length_scale_bounds='fixed'))],
#'model__length_scale':Real(0.1,10),
#'model':[GaussianProcessRegressor(kernel=RBF())],
'model__alpha':Real(0,.5),
#'model__alpha':Categorical([0,.05,.1,.2]),
'model__n_restarts_optimizer':Integer(2,50),
#'model__normalize_y':Categorical([True]),
}
param_MAT = {
'model':[GaussianProcessRegressor(kernel=1Matern(length_scale_bounds='fixed'))],
#'model':[GaussianProcessRegressor(kernel=1*Matern())],
'model__alpha':Real(0,.5),
#'model__alpha':Categorical([0,.05,.1,.2]),
'model__n_restarts_optimizer':Integer(2,50),
'model__normalize_y':Categorical([False]),

pipe_gpr = Pipeline([
('model',GaussianProcessRegressor())])

gpr_BCV = BayesSearchCV(pipe_gpr,
# (parameter space, # of evaluations)
[(param_RBF, 10), (param_MAT, 10)],verbose=1,n_jobs=-1,n_iter=repeats,n_points=s_pts,cv=kflds,scoring='neg_mean_absolute_error')
gpr_BCV.fit(X,y)
plot_convergence(gpr_BCV.optimizer_results_)

`
I'm on a windows, and these are the packages i have currently. Python 3.7.4
cycler==0.10.0
joblib==1.0.0
kiwisolver==1.3.1
matplotlib==3.3.3
numpy==1.19.3
pandas==1.1.5
Pillow==8.0.1
pp==1.6.4.4
pyaml==20.4.0
pyparsing==2.4.7
python-dateutil==2.8.1
pytz==2020.5
PyYAML==5.3.1
scikit-learn==0.23.1
scikit-optimize==0.8.1
scipy==1.6.0
seaborn==0.11.1
six==1.15.0
threadpoolctl==2.1.0

Any pointers?

[irublev]

Hi,

I see the problem is in scipy 1.6.0 (it was released 12/31/2020), reverting to, say, scipy 1.5.3 fixes this, may be considered as a temporary solution.

[nunocesarsa]

Hi,

I see the problem is in scipy 1.6.0 (it was released 12/31/2020), reverting to, say, scipy 1.5.3 fixes this, may be considered as a temporary solution.

Thank you! indeed!

[AdriaanRol]

I ran into the same problem, and it seems this is introduced by Scipy fixing this issue https://github.com/scipy/scipy/issues/13001 .

I would assume this can be fixed by removing the decode argument. Hope this helps.

[aashishtomar]

I had the same issue and downgrading to Scipy 1.5.2 solves the problem, thanks !!

[sheecegardezi]

Some where an attempt is being made to decode an object that is already decoded. Maybe putting a check might be a quick fix. Dropping the .decode('utf-8'). I think in python 3 all string an inherently Unicode but in Python 2 you had to specify unicode(''upgraded to Python 3'').

[grudloff]

Looks like this is an issue of compatibility between scikit-learn<=23.2 and scipy>=1.6.0 (see this issue). Maybe the requirements should be raised to require scikit-learn>23.2 ?