def test_get_features_names_out_classifier_error():
"""Check that error is raised when voting="soft" and flatten_transform=False."""
X = [[1, 2], [3, 4], [5, 6]]
y = [0, 1, 2]
voting = VotingClassifier(
estimators=[
("lr", LogisticRegression(random_state=0)),
("tree", DecisionTreeClassifier(random_state=0)),
],
voting="soft",
flatten_transform=False,
)
voting.fit(X, y)
msg = ("get_feature_names_out is not supported when `voting='soft'` and "
"`flatten_transform=False`")
with pytest.raises(ValueError, match=msg):
voting.get_feature_names_out()
def test_get_features_names_out_classifier(kwargs, expected_names):
"""Check get_feature_names_out for classifier for different settings."""
X = [[1, 2], [3, 4], [5, 6], [1, 1.2]]
y = [0, 1, 2, 0]
voting = VotingClassifier(
estimators=[
("lr", LogisticRegression(random_state=0)),
("tree", DecisionTreeClassifier(random_state=0)),
],
**kwargs,
)
voting.fit(X, y)
X_trans = voting.transform(X)
names_out = voting.get_feature_names_out()
assert X_trans.shape[1] == len(expected_names)
assert_array_equal(names_out, expected_names)