scikit-learn/sklearn/preprocessing/tests/test_encoders.py

691 lines
26 KiB
Python

# -*- coding: utf-8 -*-
from __future__ import division
import re
import numpy as np
from scipy import sparse
import pytest
from sklearn.exceptions import NotFittedError
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_raises_regex
from sklearn.utils.testing import assert_allclose
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import assert_warns_message
from sklearn.utils.testing import assert_no_warnings
from sklearn.preprocessing import OneHotEncoder
from sklearn.preprocessing import OrdinalEncoder
def toarray(a):
if hasattr(a, "toarray"):
a = a.toarray()
return a
def test_one_hot_encoder_sparse():
# Test OneHotEncoder's fit and transform.
X = [[3, 2, 1], [0, 1, 1]]
enc = OneHotEncoder()
with ignore_warnings(category=(DeprecationWarning, FutureWarning)):
# discover max values automatically
X_trans = enc.fit_transform(X).toarray()
assert_equal(X_trans.shape, (2, 5))
assert_array_equal(enc.active_features_,
np.where([1, 0, 0, 1, 0, 1, 1, 0, 1])[0])
assert_array_equal(enc.feature_indices_, [0, 4, 7, 9])
# check outcome
assert_array_equal(X_trans,
[[0., 1., 0., 1., 1.],
[1., 0., 1., 0., 1.]])
# max value given as 3
# enc = assert_warns(DeprecationWarning, OneHotEncoder, n_values=4)
enc = OneHotEncoder(n_values=4)
with ignore_warnings(category=DeprecationWarning):
X_trans = enc.fit_transform(X)
assert_equal(X_trans.shape, (2, 4 * 3))
assert_array_equal(enc.feature_indices_, [0, 4, 8, 12])
# max value given per feature
# enc = assert_warns(DeprecationWarning, OneHotEncoder, n_values=[3, 2, 2])
enc = OneHotEncoder(n_values=[3, 2, 2])
with ignore_warnings(category=DeprecationWarning):
X = [[1, 0, 1], [0, 1, 1]]
X_trans = enc.fit_transform(X)
assert_equal(X_trans.shape, (2, 3 + 2 + 2))
assert_array_equal(enc.n_values_, [3, 2, 2])
# check that testing with larger feature works:
X = np.array([[2, 0, 1], [0, 1, 1]])
enc.transform(X)
# test that an error is raised when out of bounds:
X_too_large = [[0, 2, 1], [0, 1, 1]]
assert_raises(ValueError, enc.transform, X_too_large)
error_msg = r"unknown categorical feature present \[2\] during transform"
assert_raises_regex(ValueError, error_msg, enc.transform, X_too_large)
with ignore_warnings(category=DeprecationWarning):
assert_raises(
ValueError,
OneHotEncoder(n_values=2).fit_transform, X)
# test that error is raised when wrong number of features
assert_raises(ValueError, enc.transform, X[:, :-1])
# test that error is raised when wrong number of features in fit
# with prespecified n_values
with ignore_warnings(category=DeprecationWarning):
assert_raises(ValueError, enc.fit, X[:, :-1])
# test exception on wrong init param
with ignore_warnings(category=DeprecationWarning):
assert_raises(
TypeError, OneHotEncoder(n_values=np.int).fit, X)
enc = OneHotEncoder()
# test negative input to fit
with ignore_warnings(category=FutureWarning):
assert_raises(ValueError, enc.fit, [[0], [-1]])
# test negative input to transform
with ignore_warnings(category=FutureWarning):
enc.fit([[0], [1]])
assert_raises(ValueError, enc.transform, [[0], [-1]])
def test_one_hot_encoder_dense():
# check for sparse=False
X = [[3, 2, 1], [0, 1, 1]]
enc = OneHotEncoder(sparse=False)
with ignore_warnings(category=(DeprecationWarning, FutureWarning)):
# discover max values automatically
X_trans = enc.fit_transform(X)
assert_equal(X_trans.shape, (2, 5))
assert_array_equal(enc.active_features_,
np.where([1, 0, 0, 1, 0, 1, 1, 0, 1])[0])
assert_array_equal(enc.feature_indices_, [0, 4, 7, 9])
# check outcome
assert_array_equal(X_trans,
np.array([[0., 1., 0., 1., 1.],
[1., 0., 1., 0., 1.]]))
def test_one_hot_encoder_deprecationwarnings():
for X in [[[3, 2, 1], [0, 1, 1]],
[[3., 2., 1.], [0., 1., 1.]]]:
enc = OneHotEncoder()
assert_warns_message(FutureWarning, "handling of integer",
enc.fit, X)
enc = OneHotEncoder()
assert_warns_message(FutureWarning, "handling of integer",
enc.fit_transform, X)
# check it still works correctly as well
with ignore_warnings(category=FutureWarning):
X_trans = enc.fit_transform(X).toarray()
res = [[0., 1., 0., 1., 1.],
[1., 0., 1., 0., 1.]]
assert_array_equal(X_trans, res)
# check deprecated attributes
assert_warns(DeprecationWarning, lambda: enc.active_features_)
assert_warns(DeprecationWarning, lambda: enc.feature_indices_)
assert_warns(DeprecationWarning, lambda: enc.n_values_)
# check no warning is raised if keyword is specified
enc = OneHotEncoder(categories='auto')
assert_no_warnings(enc.fit, X)
enc = OneHotEncoder(categories='auto')
assert_no_warnings(enc.fit_transform, X)
X_trans = enc.fit_transform(X).toarray()
assert_array_equal(X_trans, res)
# check there is also a warning if the default is passed
enc = OneHotEncoder(n_values='auto', handle_unknown='ignore')
assert_warns(DeprecationWarning, enc.fit, X)
X = np.array([['cat1', 'cat2']], dtype=object).T
enc = OneHotEncoder(categorical_features='all')
assert_warns(DeprecationWarning, enc.fit, X)
def test_one_hot_encoder_force_new_behaviour():
# ambiguous integer case (non secutive range of categories)
X = np.array([[1, 2]]).T
X2 = np.array([[0, 1]]).T
# without argument -> by default using legacy behaviour with warnings
enc = OneHotEncoder()
with ignore_warnings(category=FutureWarning):
enc.fit(X)
res = enc.transform(X2)
exp = np.array([[0, 0], [1, 0]])
assert_array_equal(res.toarray(), exp)
# with explicit auto argument -> don't use legacy behaviour
# (so will raise an error on unseen value within range)
enc = OneHotEncoder(categories='auto')
enc.fit(X)
assert_raises(ValueError, enc.transform, X2)
def _run_one_hot(X, X2, cat):
# enc = assert_warns(
# DeprecationWarning,
# OneHotEncoder, categorical_features=cat)
enc = OneHotEncoder(categorical_features=cat)
with ignore_warnings(category=(DeprecationWarning, FutureWarning)):
Xtr = enc.fit_transform(X)
with ignore_warnings(category=(DeprecationWarning, FutureWarning)):
X2tr = enc.fit(X).transform(X2)
return Xtr, X2tr
def _check_one_hot(X, X2, cat, n_features):
ind = np.where(cat)[0]
# With mask
A, B = _run_one_hot(X, X2, cat)
# With indices
C, D = _run_one_hot(X, X2, ind)
# Check shape
assert_equal(A.shape, (2, n_features))
assert_equal(B.shape, (1, n_features))
assert_equal(C.shape, (2, n_features))
assert_equal(D.shape, (1, n_features))
# Check that mask and indices give the same results
assert_array_equal(toarray(A), toarray(C))
assert_array_equal(toarray(B), toarray(D))
def test_one_hot_encoder_categorical_features():
X = np.array([[3, 2, 1], [0, 1, 1]])
X2 = np.array([[1, 1, 1]])
cat = [True, False, False]
_check_one_hot(X, X2, cat, 4)
# Edge case: all non-categorical
cat = [False, False, False]
_check_one_hot(X, X2, cat, 3)
# Edge case: all categorical
cat = [True, True, True]
_check_one_hot(X, X2, cat, 5)
# check error raised if also specifying categories
oh = OneHotEncoder(categories=[range(3)],
categorical_features=[True, False, False])
assert_raises(ValueError, oh.fit, X)
def test_one_hot_encoder_categorical_features_ignore_unknown():
# GH12881 bug in combination of categorical_features with ignore
X = np.array([[1, 2, 3], [4, 5, 6], [2, 3, 2]]).T
oh = OneHotEncoder(categorical_features=[2], handle_unknown='ignore')
with ignore_warnings(category=DeprecationWarning):
res = oh.fit_transform(X)
expected = np.array([[1, 0, 1], [0, 1, 0], [1, 2, 3], [4, 5, 6]]).T
assert_array_equal(res.toarray(), expected)
def test_one_hot_encoder_handle_unknown():
X = np.array([[0, 2, 1], [1, 0, 3], [1, 0, 2]])
X2 = np.array([[4, 1, 1]])
# Test that one hot encoder raises error for unknown features
# present during transform.
oh = OneHotEncoder(handle_unknown='error')
assert_warns(FutureWarning, oh.fit, X)
assert_raises(ValueError, oh.transform, X2)
# Test the ignore option, ignores unknown features (giving all 0's)
oh = OneHotEncoder(handle_unknown='ignore')
oh.fit(X)
X2_passed = X2.copy()
assert_array_equal(
oh.transform(X2_passed).toarray(),
np.array([[0., 0., 0., 0., 1., 0., 0.]]))
# ensure transformed data was not modified in place
assert_allclose(X2, X2_passed)
# Raise error if handle_unknown is neither ignore or error.
oh = OneHotEncoder(handle_unknown='42')
assert_raises(ValueError, oh.fit, X)
def test_one_hot_encoder_not_fitted():
X = np.array([['a'], ['b']])
enc = OneHotEncoder(categories=['a', 'b'])
msg = ("This OneHotEncoder instance is not fitted yet. "
"Call 'fit' with appropriate arguments before using this method.")
with pytest.raises(NotFittedError, match=msg):
enc.transform(X)
def test_one_hot_encoder_no_categorical_features():
X = np.array([[3, 2, 1], [0, 1, 1]], dtype='float64')
cat = [False, False, False]
enc = OneHotEncoder(categorical_features=cat)
with ignore_warnings(category=(DeprecationWarning, FutureWarning)):
X_tr = enc.fit_transform(X)
expected_features = np.array(list(), dtype='object')
assert_array_equal(X, X_tr)
assert_array_equal(enc.get_feature_names(), expected_features)
assert enc.categories_ == []
def test_one_hot_encoder_handle_unknown_strings():
X = np.array(['11111111', '22', '333', '4444']).reshape((-1, 1))
X2 = np.array(['55555', '22']).reshape((-1, 1))
# Non Regression test for the issue #12470
# Test the ignore option, when categories are numpy string dtype
# particularly when the known category strings are larger
# than the unknown category strings
oh = OneHotEncoder(handle_unknown='ignore')
oh.fit(X)
X2_passed = X2.copy()
assert_array_equal(
oh.transform(X2_passed).toarray(),
np.array([[0., 0., 0., 0.], [0., 1., 0., 0.]]))
# ensure transformed data was not modified in place
assert_array_equal(X2, X2_passed)
@pytest.mark.parametrize("output_dtype", [np.int32, np.float32, np.float64])
@pytest.mark.parametrize("input_dtype", [np.int32, np.float32, np.float64])
def test_one_hot_encoder_dtype(input_dtype, output_dtype):
X = np.asarray([[0, 1]], dtype=input_dtype).T
X_expected = np.asarray([[1, 0], [0, 1]], dtype=output_dtype)
oh = OneHotEncoder(categories='auto', dtype=output_dtype)
assert_array_equal(oh.fit_transform(X).toarray(), X_expected)
assert_array_equal(oh.fit(X).transform(X).toarray(), X_expected)
oh = OneHotEncoder(categories='auto', dtype=output_dtype, sparse=False)
assert_array_equal(oh.fit_transform(X), X_expected)
assert_array_equal(oh.fit(X).transform(X), X_expected)
@pytest.mark.parametrize("output_dtype", [np.int32, np.float32, np.float64])
def test_one_hot_encoder_dtype_pandas(output_dtype):
pd = pytest.importorskip('pandas')
X_df = pd.DataFrame({'A': ['a', 'b'], 'B': [1, 2]})
X_expected = np.array([[1, 0, 1, 0], [0, 1, 0, 1]], dtype=output_dtype)
oh = OneHotEncoder(dtype=output_dtype)
assert_array_equal(oh.fit_transform(X_df).toarray(), X_expected)
assert_array_equal(oh.fit(X_df).transform(X_df).toarray(), X_expected)
oh = OneHotEncoder(dtype=output_dtype, sparse=False)
assert_array_equal(oh.fit_transform(X_df), X_expected)
assert_array_equal(oh.fit(X_df).transform(X_df), X_expected)
def test_one_hot_encoder_set_params():
X = np.array([[1, 2]]).T
oh = OneHotEncoder()
# set params on not yet fitted object
oh.set_params(categories=[[0, 1, 2, 3]])
assert oh.get_params()['categories'] == [[0, 1, 2, 3]]
assert oh.fit_transform(X).toarray().shape == (2, 4)
# set params on already fitted object
oh.set_params(categories=[[0, 1, 2, 3, 4]])
assert oh.fit_transform(X).toarray().shape == (2, 5)
def check_categorical_onehot(X):
enc = OneHotEncoder(categories='auto')
Xtr1 = enc.fit_transform(X)
enc = OneHotEncoder(categories='auto', sparse=False)
Xtr2 = enc.fit_transform(X)
assert_allclose(Xtr1.toarray(), Xtr2)
assert sparse.isspmatrix_csr(Xtr1)
return Xtr1.toarray()
@pytest.mark.parametrize("X", [
[['def', 1, 55], ['abc', 2, 55]],
np.array([[10, 1, 55], [5, 2, 55]]),
np.array([['b', 'A', 'cat'], ['a', 'B', 'cat']], dtype=object)
], ids=['mixed', 'numeric', 'object'])
def test_one_hot_encoder(X):
Xtr = check_categorical_onehot(np.array(X)[:, [0]])
assert_allclose(Xtr, [[0, 1], [1, 0]])
Xtr = check_categorical_onehot(np.array(X)[:, [0, 1]])
assert_allclose(Xtr, [[0, 1, 1, 0], [1, 0, 0, 1]])
Xtr = OneHotEncoder(categories='auto').fit_transform(X)
assert_allclose(Xtr.toarray(), [[0, 1, 1, 0, 1], [1, 0, 0, 1, 1]])
def test_one_hot_encoder_inverse():
for sparse_ in [True, False]:
X = [['abc', 2, 55], ['def', 1, 55], ['abc', 3, 55]]
enc = OneHotEncoder(sparse=sparse_)
X_tr = enc.fit_transform(X)
exp = np.array(X, dtype=object)
assert_array_equal(enc.inverse_transform(X_tr), exp)
X = [[2, 55], [1, 55], [3, 55]]
enc = OneHotEncoder(sparse=sparse_, categories='auto')
X_tr = enc.fit_transform(X)
exp = np.array(X)
assert_array_equal(enc.inverse_transform(X_tr), exp)
# with unknown categories
X = [['abc', 2, 55], ['def', 1, 55], ['abc', 3, 55]]
enc = OneHotEncoder(sparse=sparse_, handle_unknown='ignore',
categories=[['abc', 'def'], [1, 2],
[54, 55, 56]])
X_tr = enc.fit_transform(X)
exp = np.array(X, dtype=object)
exp[2, 1] = None
assert_array_equal(enc.inverse_transform(X_tr), exp)
# with an otherwise numerical output, still object if unknown
X = [[2, 55], [1, 55], [3, 55]]
enc = OneHotEncoder(sparse=sparse_, categories=[[1, 2], [54, 56]],
handle_unknown='ignore')
X_tr = enc.fit_transform(X)
exp = np.array(X, dtype=object)
exp[2, 0] = None
exp[:, 1] = None
assert_array_equal(enc.inverse_transform(X_tr), exp)
# incorrect shape raises
X_tr = np.array([[0, 1, 1], [1, 0, 1]])
msg = re.escape('Shape of the passed X data is not correct')
assert_raises_regex(ValueError, msg, enc.inverse_transform, X_tr)
@pytest.mark.parametrize("X, cat_exp, cat_dtype", [
([['abc', 55], ['def', 55]], [['abc', 'def'], [55]], np.object_),
(np.array([[1, 2], [3, 2]]), [[1, 3], [2]], np.integer),
(np.array([['A', 'cat'], ['B', 'cat']], dtype=object),
[['A', 'B'], ['cat']], np.object_),
(np.array([['A', 'cat'], ['B', 'cat']]),
[['A', 'B'], ['cat']], np.str_)
], ids=['mixed', 'numeric', 'object', 'string'])
def test_one_hot_encoder_categories(X, cat_exp, cat_dtype):
# order of categories should not depend on order of samples
for Xi in [X, X[::-1]]:
enc = OneHotEncoder(categories='auto')
enc.fit(Xi)
# assert enc.categories == 'auto'
assert isinstance(enc.categories_, list)
for res, exp in zip(enc.categories_, cat_exp):
assert res.tolist() == exp
assert np.issubdtype(res.dtype, cat_dtype)
@pytest.mark.parametrize("X, X2, cats, cat_dtype", [
(np.array([['a', 'b']], dtype=object).T,
np.array([['a', 'd']], dtype=object).T,
[['a', 'b', 'c']], np.object_),
(np.array([[1, 2]], dtype='int64').T,
np.array([[1, 4]], dtype='int64').T,
[[1, 2, 3]], np.int64),
(np.array([['a', 'b']], dtype=object).T,
np.array([['a', 'd']], dtype=object).T,
[np.array(['a', 'b', 'c'])], np.object_),
], ids=['object', 'numeric', 'object-string-cat'])
def test_one_hot_encoder_specified_categories(X, X2, cats, cat_dtype):
enc = OneHotEncoder(categories=cats)
exp = np.array([[1., 0., 0.],
[0., 1., 0.]])
assert_array_equal(enc.fit_transform(X).toarray(), exp)
assert list(enc.categories[0]) == list(cats[0])
assert enc.categories_[0].tolist() == list(cats[0])
# manually specified categories should have same dtype as
# the data when coerced from lists
assert enc.categories_[0].dtype == cat_dtype
# when specifying categories manually, unknown categories should already
# raise when fitting
enc = OneHotEncoder(categories=cats)
with pytest.raises(ValueError, match="Found unknown categories"):
enc.fit(X2)
enc = OneHotEncoder(categories=cats, handle_unknown='ignore')
exp = np.array([[1., 0., 0.], [0., 0., 0.]])
assert_array_equal(enc.fit(X2).transform(X2).toarray(), exp)
def test_one_hot_encoder_unsorted_categories():
X = np.array([['a', 'b']], dtype=object).T
enc = OneHotEncoder(categories=[['b', 'a', 'c']])
exp = np.array([[0., 1., 0.],
[1., 0., 0.]])
assert_array_equal(enc.fit(X).transform(X).toarray(), exp)
assert_array_equal(enc.fit_transform(X).toarray(), exp)
assert enc.categories_[0].tolist() == ['b', 'a', 'c']
assert np.issubdtype(enc.categories_[0].dtype, np.object_)
# unsorted passed categories still raise for numerical values
X = np.array([[1, 2]]).T
enc = OneHotEncoder(categories=[[2, 1, 3]])
msg = 'Unsorted categories are not supported'
with pytest.raises(ValueError, match=msg):
enc.fit_transform(X)
def test_one_hot_encoder_specified_categories_mixed_columns():
# multiple columns
X = np.array([['a', 'b'], [0, 2]], dtype=object).T
enc = OneHotEncoder(categories=[['a', 'b', 'c'], [0, 1, 2]])
exp = np.array([[1., 0., 0., 1., 0., 0.],
[0., 1., 0., 0., 0., 1.]])
assert_array_equal(enc.fit_transform(X).toarray(), exp)
assert enc.categories_[0].tolist() == ['a', 'b', 'c']
assert np.issubdtype(enc.categories_[0].dtype, np.object_)
assert enc.categories_[1].tolist() == [0, 1, 2]
# integer categories but from object dtype data
assert np.issubdtype(enc.categories_[1].dtype, np.object_)
def test_one_hot_encoder_pandas():
pd = pytest.importorskip('pandas')
X_df = pd.DataFrame({'A': ['a', 'b'], 'B': [1, 2]})
Xtr = check_categorical_onehot(X_df)
assert_allclose(Xtr, [[1, 0, 1, 0], [0, 1, 0, 1]])
def test_one_hot_encoder_feature_names():
enc = OneHotEncoder()
X = [['Male', 1, 'girl', 2, 3],
['Female', 41, 'girl', 1, 10],
['Male', 51, 'boy', 12, 3],
['Male', 91, 'girl', 21, 30]]
enc.fit(X)
feature_names = enc.get_feature_names()
assert isinstance(feature_names, np.ndarray)
assert_array_equal(['x0_Female', 'x0_Male',
'x1_1', 'x1_41', 'x1_51', 'x1_91',
'x2_boy', 'x2_girl',
'x3_1', 'x3_2', 'x3_12', 'x3_21',
'x4_3',
'x4_10', 'x4_30'], feature_names)
feature_names2 = enc.get_feature_names(['one', 'two',
'three', 'four', 'five'])
assert_array_equal(['one_Female', 'one_Male',
'two_1', 'two_41', 'two_51', 'two_91',
'three_boy', 'three_girl',
'four_1', 'four_2', 'four_12', 'four_21',
'five_3', 'five_10', 'five_30'], feature_names2)
with pytest.raises(ValueError, match="input_features should have length"):
enc.get_feature_names(['one', 'two'])
def test_one_hot_encoder_feature_names_unicode():
enc = OneHotEncoder()
X = np.array([[u'c❤t1', u'dat2']], dtype=object).T
enc.fit(X)
feature_names = enc.get_feature_names()
assert_array_equal([u'x0_c❤t1', u'x0_dat2'], feature_names)
feature_names = enc.get_feature_names(input_features=[u'n👍me'])
assert_array_equal([u'n👍me_c❤t1', u'n👍me_dat2'], feature_names)
@pytest.mark.parametrize("X", [np.array([[1, np.nan]]).T,
np.array([['a', np.nan]], dtype=object).T],
ids=['numeric', 'object'])
@pytest.mark.parametrize("handle_unknown", ['error', 'ignore'])
def test_one_hot_encoder_raise_missing(X, handle_unknown):
ohe = OneHotEncoder(categories='auto', handle_unknown=handle_unknown)
with pytest.raises(ValueError, match="Input contains NaN"):
ohe.fit(X)
with pytest.raises(ValueError, match="Input contains NaN"):
ohe.fit_transform(X)
ohe.fit(X[:1, :])
with pytest.raises(ValueError, match="Input contains NaN"):
ohe.transform(X)
@pytest.mark.parametrize("X", [
[['abc', 2, 55], ['def', 1, 55]],
np.array([[10, 2, 55], [20, 1, 55]]),
np.array([['a', 'B', 'cat'], ['b', 'A', 'cat']], dtype=object)
], ids=['mixed', 'numeric', 'object'])
def test_ordinal_encoder(X):
enc = OrdinalEncoder()
exp = np.array([[0, 1, 0],
[1, 0, 0]], dtype='int64')
assert_array_equal(enc.fit_transform(X), exp.astype('float64'))
enc = OrdinalEncoder(dtype='int64')
assert_array_equal(enc.fit_transform(X), exp)
@pytest.mark.parametrize("X, X2, cats, cat_dtype", [
(np.array([['a', 'b']], dtype=object).T,
np.array([['a', 'd']], dtype=object).T,
[['a', 'b', 'c']], np.object_),
(np.array([[1, 2]], dtype='int64').T,
np.array([[1, 4]], dtype='int64').T,
[[1, 2, 3]], np.int64),
(np.array([['a', 'b']], dtype=object).T,
np.array([['a', 'd']], dtype=object).T,
[np.array(['a', 'b', 'c'])], np.object_),
], ids=['object', 'numeric', 'object-string-cat'])
def test_ordinal_encoder_specified_categories(X, X2, cats, cat_dtype):
enc = OrdinalEncoder(categories=cats)
exp = np.array([[0.], [1.]])
assert_array_equal(enc.fit_transform(X), exp)
assert list(enc.categories[0]) == list(cats[0])
assert enc.categories_[0].tolist() == list(cats[0])
# manually specified categories should have same dtype as
# the data when coerced from lists
assert enc.categories_[0].dtype == cat_dtype
# when specifying categories manually, unknown categories should already
# raise when fitting
enc = OrdinalEncoder(categories=cats)
with pytest.raises(ValueError, match="Found unknown categories"):
enc.fit(X2)
def test_ordinal_encoder_inverse():
X = [['abc', 2, 55], ['def', 1, 55]]
enc = OrdinalEncoder()
X_tr = enc.fit_transform(X)
exp = np.array(X, dtype=object)
assert_array_equal(enc.inverse_transform(X_tr), exp)
# incorrect shape raises
X_tr = np.array([[0, 1, 1, 2], [1, 0, 1, 0]])
msg = re.escape('Shape of the passed X data is not correct')
assert_raises_regex(ValueError, msg, enc.inverse_transform, X_tr)
@pytest.mark.parametrize("X", [np.array([[1, np.nan]]).T,
np.array([['a', np.nan]], dtype=object).T],
ids=['numeric', 'object'])
def test_ordinal_encoder_raise_missing(X):
ohe = OrdinalEncoder()
with pytest.raises(ValueError, match="Input contains NaN"):
ohe.fit(X)
with pytest.raises(ValueError, match="Input contains NaN"):
ohe.fit_transform(X)
ohe.fit(X[:1, :])
with pytest.raises(ValueError, match="Input contains NaN"):
ohe.transform(X)
def test_encoder_dtypes():
# check that dtypes are preserved when determining categories
enc = OneHotEncoder(categories='auto')
exp = np.array([[1., 0., 1., 0.], [0., 1., 0., 1.]], dtype='float64')
for X in [np.array([[1, 2], [3, 4]], dtype='int64'),
np.array([[1, 2], [3, 4]], dtype='float64'),
np.array([['a', 'b'], ['c', 'd']]), # string dtype
np.array([[1, 'a'], [3, 'b']], dtype='object')]:
enc.fit(X)
assert all([enc.categories_[i].dtype == X.dtype for i in range(2)])
assert_array_equal(enc.transform(X).toarray(), exp)
X = [[1, 2], [3, 4]]
enc.fit(X)
assert all([np.issubdtype(enc.categories_[i].dtype, np.integer)
for i in range(2)])
assert_array_equal(enc.transform(X).toarray(), exp)
X = [[1, 'a'], [3, 'b']]
enc.fit(X)
assert all([enc.categories_[i].dtype == 'object' for i in range(2)])
assert_array_equal(enc.transform(X).toarray(), exp)
def test_encoder_dtypes_pandas():
# check dtype (similar to test_categorical_encoder_dtypes for dataframes)
pd = pytest.importorskip('pandas')
enc = OneHotEncoder(categories='auto')
exp = np.array([[1., 0., 1., 0.], [0., 1., 0., 1.]], dtype='float64')
X = pd.DataFrame({'A': [1, 2], 'B': [3, 4]}, dtype='int64')
enc.fit(X)
assert all([enc.categories_[i].dtype == 'int64' for i in range(2)])
assert_array_equal(enc.transform(X).toarray(), exp)
X = pd.DataFrame({'A': [1, 2], 'B': ['a', 'b']})
enc.fit(X)
assert all([enc.categories_[i].dtype == 'object' for i in range(2)])
assert_array_equal(enc.transform(X).toarray(), exp)
def test_one_hot_encoder_warning():
enc = OneHotEncoder()
X = [['Male', 1], ['Female', 3]]
np.testing.assert_no_warnings(enc.fit_transform, X)