Hi all, I did manage to get the code to run using a workaround, which is bit ugly.
Following is the complete stacktrace of the error I was receiving. *Traceback (most recent call last): File "<input>", line 1, in <module> File "C:\Program Files\JetBrains\PyCharm 2020.1.1\plugins\python\helpers\pydev\_pydev_bundle\pydev_umd.py", line 197, in runfile pydev_imports.execfile(filename, global_vars, local_vars) # execute the script File "C:\Program Files\JetBrains\PyCharm 2020.1.1\plugins\python\helpers\pydev\_pydev_imps\_pydev_execfile.py", line 18, in execfile exec(compile(contents+"\n", file, 'exec'), glob, loc) File "C:/Users/ASUS/PycharmProjects/swelltest/enemble.py", line 112, in <module> ens.fit(x_train,y_train) File "C:\Users\ASUS\PycharmProjects\swelltest\venv\lib\site-packages\sklearn\ensemble\_voting.py", line 265, in fit return super().fit(X, transformed_y, sample_weight) File "C:\Users\ASUS\PycharmProjects\swelltest\venv\lib\site-packages\sklearn\ensemble\_voting.py", line 65, in fit names, clfs = self._validate_estimators() File "C:\Users\ASUS\PycharmProjects\swelltest\venv\lib\site-packages\sklearn\ensemble\_base.py", line 228, in _validate_estimators self._validate_names(names) File "C:\Users\ASUS\PycharmProjects\swelltest\venv\lib\site-packages\sklearn\utils\metaestimators.py", line 77, in _validate_names invalid_names = [name for name in names if '__' in name] File "C:\Users\ASUS\PycharmProjects\swelltest\venv\lib\site-packages\sklearn\utils\metaestimators.py", line 77, in <listcomp> invalid_names = [name for name in names if '__' in name]TypeError: argument of type 'ColumnTransformer' is not iterable* Following are the inputs in 'names' list at the time of the error. 1- *ColumnTransformer(transformers=[('phy', Pipeline(steps=[('imputer', SimpleImputer(strategy='median')), ('scaler', StandardScaler())]), ['HR', 'RMSSD', 'SCL'])])2- ColumnTransformer(transformers=[('fa',Pipeline(steps=[('imputer',SimpleImputer(strategy='median')),('scaler', StandardScaler())]),['Squality', 'Sneutral', 'Shappy'])])* Seems like that the library is attempting to search for '__' substring of the ColumnTransform object, which it is unable to perform. Since this name check doesn't have a signiticant effect on my functionality, I commented following snippet at *sklearn\utils\metaestimators.py.* *invalid_names = [name for name in names if '__' in name]if invalid_names: raise ValueError('Estimator names must not contain __: got ' '{0!r}'.format(invalid_names))* Please let me know if there is a better workaround or that their are any issues of commenting out this code. Thanks On Fri, May 29, 2020 at 10:33 AM Chamila Wijayarathna < cdwijayarat...@gmail.com> wrote: > Hello all, > > I hope I am writing to the correct mailing list about this issue that I am > having. Please apologize me if I am not. > > I am attempting to use a pipeline to feed an ensemble voting classifier as > I want the ensemble learner to use models that train on different feature > sets. For this purpose, I followed the tutorial available at [1]. > > Following is the code that I could develop so far. > > > > > > > > > > > > > > > > > > > > > > > > *y = df1.indexx = preprocessing.scale(df1)phy_features = ['A', 'B', > 'C']phy_transformer = Pipeline(steps=[('imputer', > SimpleImputer(strategy='median')), ('scaler', > StandardScaler())])phy_processer = ColumnTransformer(transformers=[('phy', > phy_transformer, phy_features)])fa_features = ['D', 'E', 'F']fa_transformer > = Pipeline(steps=[('imputer', SimpleImputer(strategy='median')), ('scaler', > StandardScaler())])fa_processer = ColumnTransformer(transformers=[('fa', > fa_transformer, fa_features)])pipe_phy = Pipeline(steps=[('preprocessor', > phy_processer ),('classifier', SVM)])pipe_fa = > Pipeline(steps=[('preprocessor', fa_processer ),('classifier', SVM)])ens = > VotingClassifier(estimators=[pipe_phy, pipe_fa])cv = KFold(n_splits=10, > random_state=None, shuffle=True)for train_index, test_index in > cv.split(x): x_train, x_test = x[train_index], x[test_index] y_train, > y_test = y[train_index], y[test_index] ens.fit(x_train,y_train) > print(ens.score(x_test, y_test))* > > However, when running the code, I am getting an error saying *TypeError: > argument of type 'ColumnTransformer' is not iterable*, at the line > *ens.fit(x_train,y_train).* > > What is the reason for this and how can I fix it? > > Thank you, > Chamila > -- Chamila Dilshan Wijayarathna, PhD Research Student The University of New South Wales (UNSW Canberra) Australian Centre for Cyber Security Australian Defence Force Academy PO Box 7916, Canberra BA ACT 2610 Australia Mobile:(+61)416895795
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