In [6]: %paste
from sklearn.linear_model import LogisticRegression
from sklearn.ensemble import RandomForestClassifier
from sklearn.svm import SVC
for y in [[0, 1], [[0], [1]]]:
    for clf in [LogisticRegression(), RandomForestClassifier(), SVC(probability=True)]:
        print(clf.__class__.__name__, y)
        clf.fit([[0], [0]], y)
        for m in ['predict', 'predict_proba', 'decision_function']:
            try:
                print(m, getattr(clf, m)([[0], [0]]).shape)
            except AttributeError:
                pass
## -- End pasted text --
LogisticRegression [0, 1]
predict (2,)
predict_proba (2, 2)
decision_function (2,)
RandomForestClassifier [0, 1]
predict (2,)
predict_proba (2, 2)
SVC [0, 1]
predict (2,)
predict_proba (2, 2)
decision_function (2,)
LogisticRegression [[0], [1]]
/Users/joel/repos/scikit-learn/sklearn/utils/validation.py:547: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples, ), for example using ravel().
  y = column_or_1d(y, warn=True)
predict (2,)
predict_proba (2, 2)
decision_function (2,)
RandomForestClassifier [[0], [1]]
/Users/joel/anaconda3/envs/scipy3k/bin/ipython:7: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().
  from IPython import start_ipython
predict (2,)
predict_proba (2, 2)
SVC [[0], [1]]
/Users/joel/repos/scikit-learn/sklearn/utils/validation.py:547: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples, ), for example using ravel().
  y = column_or_1d(y, warn=True)
predict (2,)
predict_proba (2, 2)
decision_function (2,)