Cannot persist an EvolutionarySearchCV object

[gefero]

I am trying to persist with joblib several EvolutionarySearchCV objects.
I have used this code:

`ev_search = []
it = 0
import warnings
import time
from sklearn.externals import joblib

t0 = time.time()

with warnings.catch_warnings():
warnings.simplefilter("ignore")
for n, mod, par in zip(names, mods, params):
print('Estimating ', n ,'...', sep='')
ev = EvolutionaryAlgorithmSearchCV(estimator=mod,
params=par,
scoring="roc_auc",
cv=kf,
verbose=0,
population_size=100,
gene_mutation_prob=0.10,
gene_crossover_prob=0.5,
tournament_size=3,
generations_number=10,
n_jobs=4)
ev.fit(X_train, y_train)
ev_search.append(ev)
#with open('./models_final/evv_' + n + '.pkl', 'wb') as f:
# pickle.dump(ev, f)
joblib.dump(ev, ('./models_final/evv_' + n + '.pkl'))
#print('Time elapsed:', str(t0 - time.time()))
print('Saved ', n ,' to disk', sep='')
print('----------------')
print('')
`

When I try to load it

x = joblib.load('./models_final/evv_XGBoost.pkl')

I get this error:

`---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
in ()
----> 1 x = joblib.load('./models_final/evv_XGBoost.pkl')

~/anaconda3/lib/python3.6/site-packages/sklearn/externals/joblib/numpy_pickle.py in load(filename, mmap_mode)
576 return load_compatibility(fobj)
577
--> 578 obj = _unpickle(fobj, filename, mmap_mode)
579
580 return obj

~/anaconda3/lib/python3.6/site-packages/sklearn/externals/joblib/numpy_pickle.py in _unpickle(fobj, filename, mmap_mode)
506 obj = None
507 try:
--> 508 obj = unpickler.load()
509 if unpickler.compat_mode:
510 warnings.warn("The file '%s' has been generated with a "

~/anaconda3/lib/python3.6/pickle.py in load(self)
1048 raise EOFError
1049 assert isinstance(key, bytes_types)
-> 1050 dispatchkey[0]
1051 except _Stop as stopinst:
1052 return stopinst.value

~/anaconda3/lib/python3.6/pickle.py in load_global(self)
1336 module = self.readline()[:-1].decode("utf-8")
1337 name = self.readline()[:-1].decode("utf-8")
-> 1338 klass = self.find_class(module, name)
1339 self.append(klass)
1340 dispatch[GLOBAL[0]] = load_global

~/anaconda3/lib/python3.6/pickle.py in find_class(self, module, name)
1390 return _getattribute(sys.modules[module], name)[0]
1391 else:
-> 1392 return getattr(sys.modules[module], name)
1393
1394 def load_reduce(self):

AttributeError: module 'deap.creator' has no attribute 'Individual'`