def test_make_column_transformer_pandas():
pd = pytest.importorskip('pandas')
X_array = np.array([[0, 1, 2], [2, 4, 6]]).T
X_df = pd.DataFrame(X_array, columns=['first', 'second'])
norm = Normalizer()
ct1 = ColumnTransformer([('norm', Normalizer(), X_df.columns)])
ct2 = make_column_transformer((norm, X_df.columns))
assert_almost_equal(ct1.fit_transform(X_df), ct2.fit_transform(X_df))
def test_column_transformer_mask_indexing(array_type):
# Regression test for #14510
# Boolean array-like does not behave as boolean array with NumPy < 1.12
# and sparse matrices as well
X = np.transpose([[1, 2, 3], [4, 5, 6], [5, 6, 7], [8, 9, 10]])
X = array_type(X)
column_transformer = ColumnTransformer([('identity', FunctionTransformer(),
[False, True, False, True])])
X_trans = column_transformer.fit_transform(X)
assert X_trans.shape == (3, 2)
def test_column_transformer_no_remaining_remainder_transformer():
X_array = np.array([[0, 1, 2], [2, 4, 6], [8, 6, 4]]).T
ct = ColumnTransformer([('trans1', Trans(), [0, 1, 2])],
remainder=DoubleTrans())
assert_array_equal(ct.fit_transform(X_array), X_array)
assert_array_equal(ct.fit(X_array).transform(X_array), X_array)
assert len(ct.transformers_) == 1
assert ct.transformers_[-1][0] != 'remainder'
def test_column_transformer_error_msg_1D():
X_array = np.array([[0., 1., 2.], [2., 4., 6.]]).T
col_trans = ColumnTransformer([('trans', StandardScaler(), 0)])
assert_raise_message(ValueError, "1D data passed to a transformer",
col_trans.fit, X_array)
assert_raise_message(ValueError, "1D data passed to a transformer",
col_trans.fit_transform, X_array)
col_trans = ColumnTransformer([('trans', TransRaise(), 0)])
for func in [col_trans.fit, col_trans.fit_transform]:
assert_raise_message(ValueError, "specific message", func, X_array)
def test_column_transformer_remainder_numpy(key):
# test different ways that columns are specified with passthrough
X_array = np.array([[0, 1, 2], [2, 4, 6]]).T
X_res_both = X_array
ct = ColumnTransformer([('trans1', Trans(), key)], remainder='passthrough')
assert_array_equal(ct.fit_transform(X_array), X_res_both)
assert_array_equal(ct.fit(X_array).transform(X_array), X_res_both)
assert len(ct.transformers_) == 2
assert ct.transformers_[-1][0] == 'remainder'
assert ct.transformers_[-1][1] == 'passthrough'
assert_array_equal(ct.transformers_[-1][2], [1])
def test_column_transformer_no_estimators():
X_array = np.array([[0, 1, 2], [2, 4, 6], [8, 6, 4]]).astype('float').T
ct = ColumnTransformer([], remainder=StandardScaler())
params = ct.get_params()
assert params['remainder__with_mean']
X_trans = ct.fit_transform(X_array)
assert X_trans.shape == X_array.shape
assert len(ct.transformers_) == 1
assert ct.transformers_[-1][0] == 'remainder'
assert ct.transformers_[-1][2] == [0, 1, 2]
def test_column_transformer_callable_specifier():
# assert that function gets the full array / dataframe
X_array = np.array([[0, 1, 2], [2, 4, 6]]).T
X_res_first = np.array([[0, 1, 2]]).T
def func(X):
assert_array_equal(X, X_array)
return [0]
ct = ColumnTransformer([('trans', Trans(), func)], remainder='drop')
assert_array_equal(ct.fit_transform(X_array), X_res_first)
assert_array_equal(ct.fit(X_array).transform(X_array), X_res_first)
assert callable(ct.transformers[0][2])
assert ct.transformers_[0][2] == [0]
pd = pytest.importorskip('pandas')
X_df = pd.DataFrame(X_array, columns=['first', 'second'])
def func(X):
assert_array_equal(X.columns, X_df.columns)
assert_array_equal(X.values, X_df.values)
return ['first']
ct = ColumnTransformer([('trans', Trans(), func)], remainder='drop')
assert_array_equal(ct.fit_transform(X_df), X_res_first)
assert_array_equal(ct.fit(X_df).transform(X_df), X_res_first)
assert callable(ct.transformers[0][2])
assert ct.transformers_[0][2] == ['first']
def test_column_transformer_named_estimators():
X_array = np.array([[0., 1., 2.], [2., 4., 6.]]).T
ct = ColumnTransformer([('trans1', StandardScaler(), [0]),
('trans2', StandardScaler(with_std=False), [1])])
assert not hasattr(ct, 'transformers_')
ct.fit(X_array)
assert hasattr(ct, 'transformers_')
assert isinstance(ct.named_transformers_['trans1'], StandardScaler)
assert isinstance(ct.named_transformers_.trans1, StandardScaler)
assert isinstance(ct.named_transformers_['trans2'], StandardScaler)
assert isinstance(ct.named_transformers_.trans2, StandardScaler)
assert not ct.named_transformers_.trans2.with_std
# check it are fitted transformers
assert ct.named_transformers_.trans1.mean_ == 1.
def test_column_transformer_list():
X_list = [[1, float('nan'), 'a'], [0, 0, 'b']]
expected_result = np.array([
[1, float('nan'), 1, 0],
[-1, 0, 0, 1],
])
ct = ColumnTransformer([
('numerical', StandardScaler(), [0, 1]),
('categorical', OneHotEncoder(), [2]),
])
assert_array_equal(ct.fit_transform(X_list), expected_result)
assert_array_equal(ct.fit(X_list).transform(X_list), expected_result)
def test_column_transformer_drops_all_remainder_transformer():
X_array = np.array([[0, 1, 2], [2, 4, 6], [8, 6, 4]]).T
# columns are doubled when remainder = DoubleTrans
X_res_both = 2 * X_array.copy()[:, 1:3]
ct = ColumnTransformer([('trans1', 'drop', [0])], remainder=DoubleTrans())
assert_array_equal(ct.fit_transform(X_array), X_res_both)
assert_array_equal(ct.fit(X_array).transform(X_array), X_res_both)
assert len(ct.transformers_) == 2
assert ct.transformers_[-1][0] == 'remainder'
assert isinstance(ct.transformers_[-1][1], DoubleTrans)
assert_array_equal(ct.transformers_[-1][2], [1, 2])
def test_column_transformer_remainder_transformer(key):
X_array = np.array([[0, 1, 2], [2, 4, 6], [8, 6, 4]]).T
X_res_both = X_array.copy()
# second and third columns are doubled when remainder = DoubleTrans
X_res_both[:, 1:3] *= 2
ct = ColumnTransformer([('trans1', Trans(), key)], remainder=DoubleTrans())
assert_array_equal(ct.fit_transform(X_array), X_res_both)
assert_array_equal(ct.fit(X_array).transform(X_array), X_res_both)
assert len(ct.transformers_) == 2
assert ct.transformers_[-1][0] == 'remainder'
assert isinstance(ct.transformers_[-1][1], DoubleTrans)
assert_array_equal(ct.transformers_[-1][2], [1, 2])
def test_permutation_importance_mixed_types_pandas():
pd = pytest.importorskip("pandas")
rng = np.random.RandomState(42)
n_repeats = 5
# Last column is correlated with y
X = pd.DataFrame({
'col1': [1.0, 2.0, 3.0, np.nan],
'col2': ['a', 'b', 'a', 'b']
})
y = np.array([0, 1, 0, 1])
num_preprocess = make_pipeline(SimpleImputer(), StandardScaler())
preprocess = ColumnTransformer([('num', num_preprocess, ['col1']),
('cat', OneHotEncoder(), ['col2'])])
clf = make_pipeline(preprocess, LogisticRegression(solver='lbfgs'))
clf.fit(X, y)
result = permutation_importance(clf,
X,
y,
n_repeats=n_repeats,
random_state=rng)
assert result.importances.shape == (X.shape[1], n_repeats)
# the correlated feature with y is the last column and should
# have the highest importance
assert np.all(result.importances_mean[-1] > result.importances_mean[:-1])
def test_column_transformer_drop_all_sparse_remainder_transformer():
X_array = np.array([[0, 1, 2], [2, 4, 6], [8, 6, 4]]).T
ct = ColumnTransformer([('trans1', 'drop', [0])],
remainder=SparseMatrixTrans(),
sparse_threshold=0.8)
X_trans = ct.fit_transform(X_array)
assert sparse.issparse(X_trans)
# SparseMatrixTrans creates 3 features for each column, thus:
assert X_trans.shape == (3, 3)
assert_array_equal(X_trans.toarray(), np.eye(3))
assert len(ct.transformers_) == 2
assert ct.transformers_[-1][0] == 'remainder'
assert isinstance(ct.transformers_[-1][1], SparseMatrixTrans)
assert_array_equal(ct.transformers_[-1][2], [1, 2])
def test_column_transformer_remainder_pandas(key):
# test different ways that columns are specified with passthrough
pd = pytest.importorskip('pandas')
if isinstance(key, str) and key == 'pd-index':
key = pd.Index(['first'])
X_array = np.array([[0, 1, 2], [2, 4, 6]]).T
X_df = pd.DataFrame(X_array, columns=['first', 'second'])
X_res_both = X_array
ct = ColumnTransformer([('trans1', Trans(), key)], remainder='passthrough')
assert_array_equal(ct.fit_transform(X_df), X_res_both)
assert_array_equal(ct.fit(X_df).transform(X_df), X_res_both)
assert len(ct.transformers_) == 2
assert ct.transformers_[-1][0] == 'remainder'
assert ct.transformers_[-1][1] == 'passthrough'
assert_array_equal(ct.transformers_[-1][2], [1])
def test_column_transformer_sparse_remainder_transformer():
X_array = np.array([[0, 1, 2], [2, 4, 6], [8, 6, 4]]).T
ct = ColumnTransformer([('trans1', Trans(), [0])],
remainder=SparseMatrixTrans(),
sparse_threshold=0.8)
X_trans = ct.fit_transform(X_array)
assert sparse.issparse(X_trans)
# SparseMatrixTrans creates 3 features for each column. There is
# one column in ``transformers``, thus:
assert X_trans.shape == (3, 3 + 1)
exp_array = np.hstack((X_array[:, 0].reshape(-1, 1), np.eye(3)))
assert_array_equal(X_trans.toarray(), exp_array)
assert len(ct.transformers_) == 2
assert ct.transformers_[-1][0] == 'remainder'
assert isinstance(ct.transformers_[-1][1], SparseMatrixTrans)
assert_array_equal(ct.transformers_[-1][2], [1, 2])
def test_column_transformer_cloning():
X_array = np.array([[0., 1., 2.], [2., 4., 6.]]).T
ct = ColumnTransformer([('trans', StandardScaler(), [0])])
ct.fit(X_array)
assert not hasattr(ct.transformers[0][1], 'mean_')
assert hasattr(ct.transformers_[0][1], 'mean_')
ct = ColumnTransformer([('trans', StandardScaler(), [0])])
ct.fit_transform(X_array)
assert not hasattr(ct.transformers[0][1], 'mean_')
assert hasattr(ct.transformers_[0][1], 'mean_')
def test_2D_transformer_output():
X_array = np.array([[0, 1, 2], [2, 4, 6]]).T
# if one transformer is dropped, test that name is still correct
ct = ColumnTransformer([('trans1', 'drop', 0), ('trans2', TransNo2D(), 1)])
assert_raise_message(ValueError, "the 'trans2' transformer should be 2D",
ct.fit_transform, X_array)
# because fit is also doing transform, this raises already on fit
assert_raise_message(ValueError, "the 'trans2' transformer should be 2D",
ct.fit, X_array)
def test_column_transformer_sparse_stacking():
X_array = np.array([[0, 1, 2], [2, 4, 6]]).T
col_trans = ColumnTransformer([('trans1', Trans(), [0]),
('trans2', SparseMatrixTrans(), 1)],
sparse_threshold=0.8)
col_trans.fit(X_array)
X_trans = col_trans.transform(X_array)
assert sparse.issparse(X_trans)
assert X_trans.shape == (X_trans.shape[0], X_trans.shape[0] + 1)
assert_array_equal(X_trans.toarray()[:, 1:], np.eye(X_trans.shape[0]))
assert len(col_trans.transformers_) == 2
assert col_trans.transformers_[-1][0] != 'remainder'
col_trans = ColumnTransformer([('trans1', Trans(), [0]),
('trans2', SparseMatrixTrans(), 1)],
sparse_threshold=0.1)
col_trans.fit(X_array)
X_trans = col_trans.transform(X_array)
assert not sparse.issparse(X_trans)
assert X_trans.shape == (X_trans.shape[0], X_trans.shape[0] + 1)
assert_array_equal(X_trans[:, 1:], np.eye(X_trans.shape[0]))
def test_column_transformer_invalid_transformer():
class NoTrans(BaseEstimator):
def fit(self, X, y=None):
return self
def predict(self, X):
return X
X_array = np.array([[0, 1, 2], [2, 4, 6]]).T
ct = ColumnTransformer([('trans', NoTrans(), [0])])
assert_raise_message(TypeError, "All estimators should implement fit",
ct.fit, X_array)
def test_2D_transformer_output_pandas():
pd = pytest.importorskip('pandas')
X_array = np.array([[0, 1, 2], [2, 4, 6]]).T
X_df = pd.DataFrame(X_array, columns=['col1', 'col2'])
# if one transformer is dropped, test that name is still correct
ct = ColumnTransformer([('trans1', TransNo2D(), 'col1')])
assert_raise_message(ValueError, "the 'trans1' transformer should be 2D",
ct.fit_transform, X_df)
# because fit is also doing transform, this raises already on fit
assert_raise_message(ValueError, "the 'trans1' transformer should be 2D",
ct.fit, X_df)
def test_column_transformer_reordered_column_names_remainder(explicit_colname):
"""Regression test for issue #14223: 'Named col indexing fails with
ColumnTransformer remainder on changing DataFrame column ordering'
Should raise error on changed order combined with remainder.
Should allow for added columns in `transform` input DataFrame
as long as all preceding columns match.
"""
pd = pytest.importorskip('pandas')
X_fit_array = np.array([[0, 1, 2], [2, 4, 6]]).T
X_fit_df = pd.DataFrame(X_fit_array, columns=['first', 'second'])
X_trans_array = np.array([[2, 4, 6], [0, 1, 2]]).T
X_trans_df = pd.DataFrame(X_trans_array, columns=['second', 'first'])
tf = ColumnTransformer([('bycol', Trans(), explicit_colname)],
remainder=Trans())
tf.fit(X_fit_df)
err_msg = 'Column ordering must be equal'
warn_msg = ("Given feature/column names or counts do not match the ones "
"for the data given during fit.")
with pytest.raises(ValueError, match=err_msg):
tf.transform(X_trans_df)
# No error for added columns if ordering is identical
X_extended_df = X_fit_df.copy()
X_extended_df['third'] = [3, 6, 9]
with pytest.warns(DeprecationWarning, match=warn_msg):
tf.transform(X_extended_df) # No error should be raised, for now
# No 'columns' AttributeError when transform input is a numpy array
X_array = X_fit_array.copy()
err_msg = 'Specifying the columns'
with pytest.raises(ValueError, match=err_msg):
tf.transform(X_array)
def test_column_transformer_get_set_params():
ct = ColumnTransformer([('trans1', StandardScaler(), [0]),
('trans2', StandardScaler(), [1])])
exp = {
'n_jobs': None,
'remainder': 'drop',
'sparse_threshold': 0.3,
'trans1': ct.transformers[0][1],
'trans1__copy': True,
'trans1__with_mean': True,
'trans1__with_std': True,
'trans2': ct.transformers[1][1],
'trans2__copy': True,
'trans2__with_mean': True,
'trans2__with_std': True,
'transformers': ct.transformers,
'transformer_weights': None,
'verbose': False
}
assert ct.get_params() == exp
ct.set_params(trans1__with_mean=False)
assert not ct.get_params()['trans1__with_mean']
ct.set_params(trans1='passthrough')
exp = {
'n_jobs': None,
'remainder': 'drop',
'sparse_threshold': 0.3,
'trans1': 'passthrough',
'trans2': ct.transformers[1][1],
'trans2__copy': True,
'trans2__with_mean': True,
'trans2__with_std': True,
'transformers': ct.transformers,
'transformer_weights': None,
'verbose': False
}
assert ct.get_params() == exp
def test_column_transformer_sparse_array():
X_sparse = sparse.eye(3, 2).tocsr()
# no distinction between 1D and 2D
X_res_first = X_sparse[:, 0]
X_res_both = X_sparse
for col in [0, [0], slice(0, 1)]:
for remainder, res in [('drop', X_res_first),
('passthrough', X_res_both)]:
ct = ColumnTransformer([('trans', Trans(), col)],
remainder=remainder,
sparse_threshold=0.8)
assert sparse.issparse(ct.fit_transform(X_sparse))
assert_allclose_dense_sparse(ct.fit_transform(X_sparse), res)
assert_allclose_dense_sparse(
ct.fit(X_sparse).transform(X_sparse), res)
for col in [[0, 1], slice(0, 2)]:
ct = ColumnTransformer([('trans', Trans(), col)], sparse_threshold=0.8)
assert sparse.issparse(ct.fit_transform(X_sparse))
assert_allclose_dense_sparse(ct.fit_transform(X_sparse), X_res_both)
assert_allclose_dense_sparse(
ct.fit(X_sparse).transform(X_sparse), X_res_both)
def test_column_transformer_negative_column_indexes():
X = np.random.randn(2, 2)
X_categories = np.array([[1], [2]])
X = np.concatenate([X, X_categories], axis=1)
ohe = OneHotEncoder()
tf_1 = ColumnTransformer([('ohe', ohe, [-1])], remainder='passthrough')
tf_2 = ColumnTransformer([('ohe', ohe, [2])], remainder='passthrough')
assert_array_equal(tf_1.fit_transform(X), tf_2.fit_transform(X))
def test_column_transformer():
X_array = np.array([[0, 1, 2], [2, 4, 6]]).T
X_res_first1D = np.array([0, 1, 2])
X_res_second1D = np.array([2, 4, 6])
X_res_first = X_res_first1D.reshape(-1, 1)
X_res_both = X_array
cases = [
# single column 1D / 2D
(0, X_res_first),
([0], X_res_first),
# list-like
([0, 1], X_res_both),
(np.array([0, 1]), X_res_both),
# slice
(slice(0, 1), X_res_first),
(slice(0, 2), X_res_both),
# boolean mask
(np.array([True, False]), X_res_first),
]
for selection, res in cases:
ct = ColumnTransformer([('trans', Trans(), selection)],
remainder='drop')
assert_array_equal(ct.fit_transform(X_array), res)
assert_array_equal(ct.fit(X_array).transform(X_array), res)
# callable that returns any of the allowed specifiers
ct = ColumnTransformer([('trans', Trans(), lambda x: selection)],
remainder='drop')
assert_array_equal(ct.fit_transform(X_array), res)
assert_array_equal(ct.fit(X_array).transform(X_array), res)
ct = ColumnTransformer([('trans1', Trans(), [0]),
('trans2', Trans(), [1])])
assert_array_equal(ct.fit_transform(X_array), X_res_both)
assert_array_equal(ct.fit(X_array).transform(X_array), X_res_both)
assert len(ct.transformers_) == 2
# test with transformer_weights
transformer_weights = {'trans1': .1, 'trans2': 10}
both = ColumnTransformer([('trans1', Trans(), [0]),
('trans2', Trans(), [1])],
transformer_weights=transformer_weights)
res = np.vstack([
transformer_weights['trans1'] * X_res_first1D,
transformer_weights['trans2'] * X_res_second1D
]).T
assert_array_equal(both.fit_transform(X_array), res)
assert_array_equal(both.fit(X_array).transform(X_array), res)
assert len(both.transformers_) == 2
both = ColumnTransformer([('trans', Trans(), [0, 1])],
transformer_weights={'trans': .1})
assert_array_equal(both.fit_transform(X_array), 0.1 * X_res_both)
assert_array_equal(both.fit(X_array).transform(X_array), 0.1 * X_res_both)
assert len(both.transformers_) == 1
def test_column_transformer_special_strings():
# one 'drop' -> ignore
X_array = np.array([[0., 1., 2.], [2., 4., 6.]]).T
ct = ColumnTransformer([('trans1', Trans(), [0]), ('trans2', 'drop', [1])])
exp = np.array([[0.], [1.], [2.]])
assert_array_equal(ct.fit_transform(X_array), exp)
assert_array_equal(ct.fit(X_array).transform(X_array), exp)
assert len(ct.transformers_) == 2
assert ct.transformers_[-1][0] != 'remainder'
# all 'drop' -> return shape 0 array
ct = ColumnTransformer([('trans1', 'drop', [0]), ('trans2', 'drop', [1])])
assert_array_equal(ct.fit(X_array).transform(X_array).shape, (3, 0))
assert_array_equal(ct.fit_transform(X_array).shape, (3, 0))
assert len(ct.transformers_) == 2
assert ct.transformers_[-1][0] != 'remainder'
# 'passthrough'
X_array = np.array([[0., 1., 2.], [2., 4., 6.]]).T
ct = ColumnTransformer([('trans1', Trans(), [0]),
('trans2', 'passthrough', [1])])
exp = X_array
assert_array_equal(ct.fit_transform(X_array), exp)
assert_array_equal(ct.fit(X_array).transform(X_array), exp)
assert len(ct.transformers_) == 2
assert ct.transformers_[-1][0] != 'remainder'
# None itself / other string is not valid
for val in [None, 'other']:
ct = ColumnTransformer([('trans1', Trans(), [0]),
('trans2', None, [1])])
assert_raise_message(TypeError, "All estimators should implement",
ct.fit_transform, X_array)
assert_raise_message(TypeError, "All estimators should implement",
ct.fit, X_array)
def test_column_transformer_get_feature_names():
X_array = np.array([[0., 1., 2.], [2., 4., 6.]]).T
ct = ColumnTransformer([('trans', Trans(), [0, 1])])
# raise correct error when not fitted
with pytest.raises(NotFittedError):
ct.get_feature_names()
# raise correct error when no feature names are available
ct.fit(X_array)
assert_raise_message(
AttributeError, "Transformer trans (type Trans) does not provide "
"get_feature_names", ct.get_feature_names)
# working example
X = np.array([[{
'a': 1,
'b': 2
}, {
'a': 3,
'b': 4
}], [{
'c': 5
}, {
'c': 6
}]],
dtype=object).T
ct = ColumnTransformer([('col' + str(i), DictVectorizer(), i)
for i in range(2)])
ct.fit(X)
assert ct.get_feature_names() == ['col0__a', 'col0__b', 'col1__c']
# passthrough transformers not supported
ct = ColumnTransformer([('trans', 'passthrough', [0, 1])])
ct.fit(X)
assert_raise_message(NotImplementedError,
'get_feature_names is not yet supported',
ct.get_feature_names)
ct = ColumnTransformer([('trans', DictVectorizer(), 0)],
remainder='passthrough')
ct.fit(X)
assert_raise_message(NotImplementedError,
'get_feature_names is not yet supported',
ct.get_feature_names)
# drop transformer
ct = ColumnTransformer([('col0', DictVectorizer(), 0),
('col1', 'drop', 1)])
ct.fit(X)
assert ct.get_feature_names() == ['col0__a', 'col0__b']
def test_column_transformer_sparse_threshold():
X_array = np.array([['a', 'b'], ['A', 'B']], dtype=object).T
# above data has sparsity of 4 / 8 = 0.5
# apply threshold even if all sparse
col_trans = ColumnTransformer([('trans1', OneHotEncoder(), [0]),
('trans2', OneHotEncoder(), [1])],
sparse_threshold=0.2)
res = col_trans.fit_transform(X_array)
assert not sparse.issparse(res)
assert not col_trans.sparse_output_
# mixed -> sparsity of (4 + 2) / 8 = 0.75
for thres in [0.75001, 1]:
col_trans = ColumnTransformer(
[('trans1', OneHotEncoder(sparse=True), [0]),
('trans2', OneHotEncoder(sparse=False), [1])],
sparse_threshold=thres)
res = col_trans.fit_transform(X_array)
assert sparse.issparse(res)
assert col_trans.sparse_output_
for thres in [0.75, 0]:
col_trans = ColumnTransformer(
[('trans1', OneHotEncoder(sparse=True), [0]),
('trans2', OneHotEncoder(sparse=False), [1])],
sparse_threshold=thres)
res = col_trans.fit_transform(X_array)
assert not sparse.issparse(res)
assert not col_trans.sparse_output_
# if nothing is sparse -> no sparse
for thres in [0.33, 0, 1]:
col_trans = ColumnTransformer(
[('trans1', OneHotEncoder(sparse=False), [0]),
('trans2', OneHotEncoder(sparse=False), [1])],
sparse_threshold=thres)
res = col_trans.fit_transform(X_array)
assert not sparse.issparse(res)
assert not col_trans.sparse_output_
def test_column_transformer_remainder():
X_array = np.array([[0, 1, 2], [2, 4, 6]]).T
X_res_first = np.array([0, 1, 2]).reshape(-1, 1)
X_res_second = np.array([2, 4, 6]).reshape(-1, 1)
X_res_both = X_array
# default drop
ct = ColumnTransformer([('trans1', Trans(), [0])])
assert_array_equal(ct.fit_transform(X_array), X_res_first)
assert_array_equal(ct.fit(X_array).transform(X_array), X_res_first)
assert len(ct.transformers_) == 2
assert ct.transformers_[-1][0] == 'remainder'
assert ct.transformers_[-1][1] == 'drop'
assert_array_equal(ct.transformers_[-1][2], [1])
# specify passthrough
ct = ColumnTransformer([('trans', Trans(), [0])], remainder='passthrough')
assert_array_equal(ct.fit_transform(X_array), X_res_both)
assert_array_equal(ct.fit(X_array).transform(X_array), X_res_both)
assert len(ct.transformers_) == 2
assert ct.transformers_[-1][0] == 'remainder'
assert ct.transformers_[-1][1] == 'passthrough'
assert_array_equal(ct.transformers_[-1][2], [1])
# column order is not preserved (passed through added to end)
ct = ColumnTransformer([('trans1', Trans(), [1])], remainder='passthrough')
assert_array_equal(ct.fit_transform(X_array), X_res_both[:, ::-1])
assert_array_equal(ct.fit(X_array).transform(X_array), X_res_both[:, ::-1])
assert len(ct.transformers_) == 2
assert ct.transformers_[-1][0] == 'remainder'
assert ct.transformers_[-1][1] == 'passthrough'
assert_array_equal(ct.transformers_[-1][2], [0])
# passthrough when all actual transformers are skipped
ct = ColumnTransformer([('trans1', 'drop', [0])], remainder='passthrough')
assert_array_equal(ct.fit_transform(X_array), X_res_second)
assert_array_equal(ct.fit(X_array).transform(X_array), X_res_second)
assert len(ct.transformers_) == 2
assert ct.transformers_[-1][0] == 'remainder'
assert ct.transformers_[-1][1] == 'passthrough'
assert_array_equal(ct.transformers_[-1][2], [1])
# error on invalid arg
ct = ColumnTransformer([('trans1', Trans(), [0])], remainder=1)
assert_raise_message(
ValueError,
"remainder keyword needs to be one of \'drop\', \'passthrough\', "
"or estimator.", ct.fit, X_array)
assert_raise_message(
ValueError,
"remainder keyword needs to be one of \'drop\', \'passthrough\', "
"or estimator.", ct.fit_transform, X_array)
# check default for make_column_transformer
ct = make_column_transformer((Trans(), [0]))
assert ct.remainder == 'drop'
def test_column_transformer_invalid_columns(remainder):
X_array = np.array([[0, 1, 2], [2, 4, 6]]).T
# general invalid
for col in [1.5, ['string', 1], slice(1, 's'), np.array([1.])]:
ct = ColumnTransformer([('trans', Trans(), col)], remainder=remainder)
assert_raise_message(ValueError, "No valid specification", ct.fit,
X_array)
# invalid for arrays
for col in ['string', ['string', 'other'], slice('a', 'b')]:
ct = ColumnTransformer([('trans', Trans(), col)], remainder=remainder)
assert_raise_message(ValueError, "Specifying the columns", ct.fit,
X_array)
# transformed n_features does not match fitted n_features
col = [0, 1]
ct = ColumnTransformer([('trans', Trans(), col)], remainder=remainder)
ct.fit(X_array)
X_array_more = np.array([[0, 1, 2], [2, 4, 6], [3, 6, 9]]).T
msg = ("Given feature/column names or counts do not match the ones for "
"the data given during fit.")
with pytest.warns(DeprecationWarning, match=msg):
ct.transform(X_array_more) # Should accept added columns, for now
X_array_fewer = np.array([
[0, 1, 2],
]).T
err_msg = 'Number of features'
with pytest.raises(ValueError, match=err_msg):
ct.transform(X_array_fewer)
