我正在尝试根据本教程的指导为 Python sklearn 管道创建自定义转换器:http://danielhnyk.cz/creating-your-own-estimator-scikit-learn/
现在我的自定义类/变压器如下所示:
class SelectBestPercFeats(BaseEstimator, TransformerMixin):
def __init__(self, model=RandomForestRegressor(), percent=0.8,
random_state=52):
self.model = model
self.percent = percent
self.random_state = random_state
def fit(self, X, y, **fit_params):
"""
Find features with best predictive power for the model, and
have cumulative importance value less than self.percent
"""
# Check parameters
if not isinstance(self.percent, float):
print("SelectBestPercFeats.percent is not a float, it should be...")
elif not isinstance(self.random_state, int):
print("SelectBestPercFeats.random_state is not a int, it should be...")
# If checks are good proceed with fitting...
else:
try:
self.model.fit(X, y)
except:
print("Error fitting model inside SelectBestPercFeats object")
return self
# Get feature importance
try:
feat_imp = list(self.model.feature_importances_)
feat_imp_cum = pd.Series(feat_imp, index=X.columns) \
.sort_values(ascending=False).cumsum()
# Get features whose cumulative importance is <= `percent`
n_feats = len(feat_imp_cum[feat_imp_cum <= self.percent].index) + 1
self.bestcolumns_ = list(feat_imp_cum.index)[:n_feats]
except:
print ("ERROR: SelectBestPercFeats can only be used with models with"\
" .feature_importances_ parameter")
return self
def transform(self, X, y=None, **fit_params):
"""
Filter out only the important features (based on percent threshold)
for the model supplied.
:param X: Dataframe with features to be down selected
"""
if self.bestcolumns_ is None:
print("Must call fit function on SelectBestPercFeats object before transforming")
else:
return X[self.bestcolumns_]
我正在将此类集成到 sklearn 管道中,如下所示:
# Define feature selection and model pipeline components
rf_simp = RandomForestRegressor(criterion='mse', n_jobs=-1,
n_estimators=600)
bestfeat = SelectBestPercFeats(rf_simp, feat_perc)
rf = RandomForestRegressor(n_jobs=-1,
criterion='mse',
n_estimators=200,
max_features=0.4,
)
# Build Pipeline
master_model = Pipeline([('feat_sel', bestfeat), ('rf', rf)])
# define GridSearchCV parameter space to search,
# only listing one parameter to simplify troubleshooting
param_grid = {
'feat_select__percent': [0.8],
}
# Fit pipeline model
grid = GridSearchCV(master_model, cv=3, n_jobs=-1,
param_grid=param_grid)
# Search grid using CV, and get the best estimator
grid.fit(X_train, y_train)
每当我运行最后一行代码时(grid.fit(X_train, y_train)
)我收到以下“PicklingError”。任何人都可以看到我的代码中导致此问题的原因是什么?
EDIT:
或者,我的 Python 设置中是否存在错误......我可能缺少一个包或类似的东西吗?我刚刚检查过我可以import pickle
成功地
回溯(最近一次调用):文件“”,第 5 行,位于
文件
“C:\ Users \ jjaaae \ AppData \ Local \ Programs \ Python \ Python36 \ lib \ site-packages \ sklearn \ model_selection_search.py”,
945 行,适合
返回 self._fit(X, y, groups, ParameterGrid(self.param_grid)) 文件
“C:\ Users \ jjaaae \ AppData \ Local \ Programs \ Python \ Python36 \ lib \ site-packages \ sklearn \ model_selection_search.py”,
第 564 行,在 _fit 中
对于parameter_iterable文件“C:\ Users \ jjaaae \ AppData \ Local \ Programs \ Python \ Python36 \ lib \ site-packages \ sklearn \ externals \ joblib \ parallel.py”中的参数,
768 号线,在callself.retrieve() 文件“C:\Users\jjaaae\AppData\Local\Programs\Python\Python36\lib\site-packages\sklearn\externals\joblib\parallel.py”,
第 719 行,在检索中
引发异常文件“C:\ Users \ jjaaae \ AppData \ Local \ Programs \ Python \ Python36 \ lib \ site-packages \ sklearn \ externals \ joblib \ parallel.py”,
第 682 行,在检索中
self._output.extend(job.get(timeout=self.timeout)) 文件“C:\Users\jjaaae\AppData\Local\Programs\Python\Python36\lib\multiprocessing\pool.py”,
第 608 行,在 get 中
提高 self._value 文件“C:\Users\jjaaae\AppData\Local\Programs\Python\Python36\lib\multiprocessing\pool.py”,
第 385 行,在 _handle_tasks 中
put(任务)文件“C:\ Users \ jjaaae \ AppData \ Local \ Programs \ Python \ Python36 \ lib \ site-packages \ sklearn \ externals \ joblib \ pool.py”,
第 371 行,发送中
CustomizedPickler(buffer, self._reducers).dump(obj)
_pickle.PicklingError:无法 pickle:内置函数上的属性查找 SelectBestPercFeats 失败