8th day of python challenges 111-117

venv/lib/python3.6/site-packages/pandas/tests/arrays/categorical/common.py

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+from pandas import Categorical
+
+
+class TestCategorical:
+    def setup_method(self, method):
+        self.factor = Categorical(
+            ["a", "b", "b", "a", "a", "c", "c", "c"], ordered=True
+        )

venv/lib/python3.6/site-packages/pandas/tests/arrays/categorical/conftest.py

@@ -0,0 +1,7 @@
+import pytest
+
+
+@pytest.fixture(params=[True, False])
+def allow_fill(request):
+    """Boolean 'allow_fill' parameter for Categorical.take"""
+    return request.param

venv/lib/python3.6/site-packages/pandas/tests/arrays/categorical/test_algos.py

@@ -0,0 +1,142 @@
+import numpy as np
+import pytest
+
+import pandas as pd
+import pandas.util.testing as tm
+
+
+@pytest.mark.parametrize("ordered", [True, False])
+@pytest.mark.parametrize("categories", [["b", "a", "c"], ["a", "b", "c", "d"]])
+def test_factorize(categories, ordered):
+    cat = pd.Categorical(
+        ["b", "b", "a", "c", None], categories=categories, ordered=ordered
+    )
+    labels, uniques = pd.factorize(cat)
+    expected_labels = np.array([0, 0, 1, 2, -1], dtype=np.intp)
+    expected_uniques = pd.Categorical(
+        ["b", "a", "c"], categories=categories, ordered=ordered
+    )
+
+    tm.assert_numpy_array_equal(labels, expected_labels)
+    tm.assert_categorical_equal(uniques, expected_uniques)
+
+
+def test_factorized_sort():
+    cat = pd.Categorical(["b", "b", None, "a"])
+    labels, uniques = pd.factorize(cat, sort=True)
+    expected_labels = np.array([1, 1, -1, 0], dtype=np.intp)
+    expected_uniques = pd.Categorical(["a", "b"])
+
+    tm.assert_numpy_array_equal(labels, expected_labels)
+    tm.assert_categorical_equal(uniques, expected_uniques)
+
+
+def test_factorized_sort_ordered():
+    cat = pd.Categorical(
+        ["b", "b", None, "a"], categories=["c", "b", "a"], ordered=True
+    )
+
+    labels, uniques = pd.factorize(cat, sort=True)
+    expected_labels = np.array([0, 0, -1, 1], dtype=np.intp)
+    expected_uniques = pd.Categorical(
+        ["b", "a"], categories=["c", "b", "a"], ordered=True
+    )
+
+    tm.assert_numpy_array_equal(labels, expected_labels)
+    tm.assert_categorical_equal(uniques, expected_uniques)
+
+
+def test_isin_cats():
+    # GH2003
+    cat = pd.Categorical(["a", "b", np.nan])
+
+    result = cat.isin(["a", np.nan])
+    expected = np.array([True, False, True], dtype=bool)
+    tm.assert_numpy_array_equal(expected, result)
+
+    result = cat.isin(["a", "c"])
+    expected = np.array([True, False, False], dtype=bool)
+    tm.assert_numpy_array_equal(expected, result)
+
+
+@pytest.mark.parametrize("empty", [[], pd.Series(), np.array([])])
+def test_isin_empty(empty):
+    s = pd.Categorical(["a", "b"])
+    expected = np.array([False, False], dtype=bool)
+
+    result = s.isin(empty)
+    tm.assert_numpy_array_equal(expected, result)
+
+
+class TestTake:
+    # https://github.com/pandas-dev/pandas/issues/20664
+
+    def test_take_warns(self):
+        cat = pd.Categorical(["a", "b"])
+        with tm.assert_produces_warning(FutureWarning):
+            cat.take([0, -1])
+
+    def test_take_positive_no_warning(self):
+        cat = pd.Categorical(["a", "b"])
+        with tm.assert_produces_warning(None):
+            cat.take([0, 0])
+
+    def test_take_bounds(self, allow_fill):
+        # https://github.com/pandas-dev/pandas/issues/20664
+        cat = pd.Categorical(["a", "b", "a"])
+        with pytest.raises(IndexError):
+            cat.take([4, 5], allow_fill=allow_fill)
+
+    def test_take_empty(self, allow_fill):
+        # https://github.com/pandas-dev/pandas/issues/20664
+        cat = pd.Categorical([], categories=["a", "b"])
+        with pytest.raises(IndexError):
+            cat.take([0], allow_fill=allow_fill)
+
+    def test_positional_take(self, ordered_fixture):
+        cat = pd.Categorical(
+            ["a", "a", "b", "b"], categories=["b", "a"], ordered=ordered_fixture
+        )
+        result = cat.take([0, 1, 2], allow_fill=False)
+        expected = pd.Categorical(
+            ["a", "a", "b"], categories=cat.categories, ordered=ordered_fixture
+        )
+        tm.assert_categorical_equal(result, expected)
+
+    def test_positional_take_unobserved(self, ordered_fixture):
+        cat = pd.Categorical(
+            ["a", "b"], categories=["a", "b", "c"], ordered=ordered_fixture
+        )
+        result = cat.take([1, 0], allow_fill=False)
+        expected = pd.Categorical(
+            ["b", "a"], categories=cat.categories, ordered=ordered_fixture
+        )
+        tm.assert_categorical_equal(result, expected)
+
+    def test_take_allow_fill(self):
+        # https://github.com/pandas-dev/pandas/issues/23296
+        cat = pd.Categorical(["a", "a", "b"])
+        result = cat.take([0, -1, -1], allow_fill=True)
+        expected = pd.Categorical(["a", np.nan, np.nan], categories=["a", "b"])
+        tm.assert_categorical_equal(result, expected)
+
+    def test_take_fill_with_negative_one(self):
+        # -1 was a category
+        cat = pd.Categorical([-1, 0, 1])
+        result = cat.take([0, -1, 1], allow_fill=True, fill_value=-1)
+        expected = pd.Categorical([-1, -1, 0], categories=[-1, 0, 1])
+        tm.assert_categorical_equal(result, expected)
+
+    def test_take_fill_value(self):
+        # https://github.com/pandas-dev/pandas/issues/23296
+        cat = pd.Categorical(["a", "b", "c"])
+        result = cat.take([0, 1, -1], fill_value="a", allow_fill=True)
+        expected = pd.Categorical(["a", "b", "a"], categories=["a", "b", "c"])
+        tm.assert_categorical_equal(result, expected)
+
+    def test_take_fill_value_new_raises(self):
+        # https://github.com/pandas-dev/pandas/issues/23296
+        cat = pd.Categorical(["a", "b", "c"])
+        xpr = r"'fill_value' \('d'\) is not in this Categorical's categories."
+        with pytest.raises(TypeError, match=xpr):
+            cat.take([0, 1, -1], fill_value="d", allow_fill=True)

venv/lib/python3.6/site-packages/pandas/tests/arrays/categorical/test_analytics.py

@@ -0,0 +1,316 @@
+import sys
+
+import numpy as np
+import pytest
+
+from pandas.compat import PYPY
+
+from pandas import Categorical, Index, Series
+from pandas.api.types import is_scalar
+import pandas.util.testing as tm
+
+
+class TestCategoricalAnalytics:
+    def test_min_max(self):
+
+        # unordered cats have no min/max
+        cat = Categorical(["a", "b", "c", "d"], ordered=False)
+        msg = "Categorical is not ordered for operation {}"
+        with pytest.raises(TypeError, match=msg.format("min")):
+            cat.min()
+        with pytest.raises(TypeError, match=msg.format("max")):
+            cat.max()
+
+        cat = Categorical(["a", "b", "c", "d"], ordered=True)
+        _min = cat.min()
+        _max = cat.max()
+        assert _min == "a"
+        assert _max == "d"
+
+        cat = Categorical(
+            ["a", "b", "c", "d"], categories=["d", "c", "b", "a"], ordered=True
+        )
+        _min = cat.min()
+        _max = cat.max()
+        assert _min == "d"
+        assert _max == "a"
+
+        cat = Categorical(
+            [np.nan, "b", "c", np.nan], categories=["d", "c", "b", "a"], ordered=True
+        )
+        _min = cat.min()
+        _max = cat.max()
+        assert np.isnan(_min)
+        assert _max == "b"
+
+        _min = cat.min(numeric_only=True)
+        assert _min == "c"
+        _max = cat.max(numeric_only=True)
+        assert _max == "b"
+
+        cat = Categorical(
+            [np.nan, 1, 2, np.nan], categories=[5, 4, 3, 2, 1], ordered=True
+        )
+        _min = cat.min()
+        _max = cat.max()
+        assert np.isnan(_min)
+        assert _max == 1
+
+        _min = cat.min(numeric_only=True)
+        assert _min == 2
+        _max = cat.max(numeric_only=True)
+        assert _max == 1
+
+    @pytest.mark.parametrize(
+        "values,categories,exp_mode",
+        [
+            ([1, 1, 2, 4, 5, 5, 5], [5, 4, 3, 2, 1], [5]),
+            ([1, 1, 1, 4, 5, 5, 5], [5, 4, 3, 2, 1], [5, 1]),
+            ([1, 2, 3, 4, 5], [5, 4, 3, 2, 1], [5, 4, 3, 2, 1]),
+            ([np.nan, np.nan, np.nan, 4, 5], [5, 4, 3, 2, 1], [5, 4]),
+            ([np.nan, np.nan, np.nan, 4, 5, 4], [5, 4, 3, 2, 1], [4]),
+            ([np.nan, np.nan, 4, 5, 4], [5, 4, 3, 2, 1], [4]),
+        ],
+    )
+    def test_mode(self, values, categories, exp_mode):
+        s = Categorical(values, categories=categories, ordered=True)
+        res = s.mode()
+        exp = Categorical(exp_mode, categories=categories, ordered=True)
+        tm.assert_categorical_equal(res, exp)
+
+    def test_searchsorted(self):
+        # https://github.com/pandas-dev/pandas/issues/8420
+        # https://github.com/pandas-dev/pandas/issues/14522
+
+        c1 = Categorical(
+            ["cheese", "milk", "apple", "bread", "bread"],
+            categories=["cheese", "milk", "apple", "bread"],
+            ordered=True,
+        )
+        s1 = Series(c1)
+        c2 = Categorical(
+            ["cheese", "milk", "apple", "bread", "bread"],
+            categories=["cheese", "milk", "apple", "bread"],
+            ordered=False,
+        )
+        s2 = Series(c2)
+
+        # Searching for single item argument, side='left' (default)
+        res_cat = c1.searchsorted("apple")
+        assert res_cat == 2
+        assert is_scalar(res_cat)
+
+        res_ser = s1.searchsorted("apple")
+        assert res_ser == 2
+        assert is_scalar(res_ser)
+
+        # Searching for single item array, side='left' (default)
+        res_cat = c1.searchsorted(["bread"])
+        res_ser = s1.searchsorted(["bread"])
+        exp = np.array([3], dtype=np.intp)
+        tm.assert_numpy_array_equal(res_cat, exp)
+        tm.assert_numpy_array_equal(res_ser, exp)
+
+        # Searching for several items array, side='right'
+        res_cat = c1.searchsorted(["apple", "bread"], side="right")
+        res_ser = s1.searchsorted(["apple", "bread"], side="right")
+        exp = np.array([3, 5], dtype=np.intp)
+        tm.assert_numpy_array_equal(res_cat, exp)
+        tm.assert_numpy_array_equal(res_ser, exp)
+
+        # Searching for a single value that is not from the Categorical
+        msg = r"Value\(s\) to be inserted must be in categories"
+        with pytest.raises(KeyError, match=msg):
+            c1.searchsorted("cucumber")
+        with pytest.raises(KeyError, match=msg):
+            s1.searchsorted("cucumber")
+
+        # Searching for multiple values one of each is not from the Categorical
+        with pytest.raises(KeyError, match=msg):
+            c1.searchsorted(["bread", "cucumber"])
+        with pytest.raises(KeyError, match=msg):
+            s1.searchsorted(["bread", "cucumber"])
+
+        # searchsorted call for unordered Categorical
+        msg = "Categorical not ordered"
+        with pytest.raises(ValueError, match=msg):
+            c2.searchsorted("apple")
+        with pytest.raises(ValueError, match=msg):
+            s2.searchsorted("apple")
+
+    def test_unique(self):
+        # categories are reordered based on value when ordered=False
+        cat = Categorical(["a", "b"])
+        exp = Index(["a", "b"])
+        res = cat.unique()
+        tm.assert_index_equal(res.categories, exp)
+        tm.assert_categorical_equal(res, cat)
+
+        cat = Categorical(["a", "b", "a", "a"], categories=["a", "b", "c"])
+        res = cat.unique()
+        tm.assert_index_equal(res.categories, exp)
+        tm.assert_categorical_equal(res, Categorical(exp))
+
+        cat = Categorical(["c", "a", "b", "a", "a"], categories=["a", "b", "c"])
+        exp = Index(["c", "a", "b"])
+        res = cat.unique()
+        tm.assert_index_equal(res.categories, exp)
+        exp_cat = Categorical(exp, categories=["c", "a", "b"])
+        tm.assert_categorical_equal(res, exp_cat)
+
+        # nan must be removed
+        cat = Categorical(["b", np.nan, "b", np.nan, "a"], categories=["a", "b", "c"])
+        res = cat.unique()
+        exp = Index(["b", "a"])
+        tm.assert_index_equal(res.categories, exp)
+        exp_cat = Categorical(["b", np.nan, "a"], categories=["b", "a"])
+        tm.assert_categorical_equal(res, exp_cat)
+
+    def test_unique_ordered(self):
+        # keep categories order when ordered=True
+        cat = Categorical(["b", "a", "b"], categories=["a", "b"], ordered=True)
+        res = cat.unique()
+        exp_cat = Categorical(["b", "a"], categories=["a", "b"], ordered=True)
+        tm.assert_categorical_equal(res, exp_cat)
+
+        cat = Categorical(
+            ["c", "b", "a", "a"], categories=["a", "b", "c"], ordered=True
+        )
+        res = cat.unique()
+        exp_cat = Categorical(["c", "b", "a"], categories=["a", "b", "c"], ordered=True)
+        tm.assert_categorical_equal(res, exp_cat)
+
+        cat = Categorical(["b", "a", "a"], categories=["a", "b", "c"], ordered=True)
+        res = cat.unique()
+        exp_cat = Categorical(["b", "a"], categories=["a", "b"], ordered=True)
+        tm.assert_categorical_equal(res, exp_cat)
+
+        cat = Categorical(
+            ["b", "b", np.nan, "a"], categories=["a", "b", "c"], ordered=True
+        )
+        res = cat.unique()
+        exp_cat = Categorical(["b", np.nan, "a"], categories=["a", "b"], ordered=True)
+        tm.assert_categorical_equal(res, exp_cat)
+
+    def test_unique_index_series(self):
+        c = Categorical([3, 1, 2, 2, 1], categories=[3, 2, 1])
+        # Categorical.unique sorts categories by appearance order
+        # if ordered=False
+        exp = Categorical([3, 1, 2], categories=[3, 1, 2])
+        tm.assert_categorical_equal(c.unique(), exp)
+
+        tm.assert_index_equal(Index(c).unique(), Index(exp))
+        tm.assert_categorical_equal(Series(c).unique(), exp)
+
+        c = Categorical([1, 1, 2, 2], categories=[3, 2, 1])
+        exp = Categorical([1, 2], categories=[1, 2])
+        tm.assert_categorical_equal(c.unique(), exp)
+        tm.assert_index_equal(Index(c).unique(), Index(exp))
+        tm.assert_categorical_equal(Series(c).unique(), exp)
+
+        c = Categorical([3, 1, 2, 2, 1], categories=[3, 2, 1], ordered=True)
+        # Categorical.unique keeps categories order if ordered=True
+        exp = Categorical([3, 1, 2], categories=[3, 2, 1], ordered=True)
+        tm.assert_categorical_equal(c.unique(), exp)
+
+        tm.assert_index_equal(Index(c).unique(), Index(exp))
+        tm.assert_categorical_equal(Series(c).unique(), exp)
+
+    def test_shift(self):
+        # GH 9416
+        cat = Categorical(["a", "b", "c", "d", "a"])
+
+        # shift forward
+        sp1 = cat.shift(1)
+        xp1 = Categorical([np.nan, "a", "b", "c", "d"])
+        tm.assert_categorical_equal(sp1, xp1)
+        tm.assert_categorical_equal(cat[:-1], sp1[1:])
+
+        # shift back
+        sn2 = cat.shift(-2)
+        xp2 = Categorical(
+            ["c", "d", "a", np.nan, np.nan], categories=["a", "b", "c", "d"]
+        )
+        tm.assert_categorical_equal(sn2, xp2)
+        tm.assert_categorical_equal(cat[2:], sn2[:-2])
+
+        # shift by zero
+        tm.assert_categorical_equal(cat, cat.shift(0))
+
+    def test_nbytes(self):
+        cat = Categorical([1, 2, 3])
+        exp = 3 + 3 * 8  # 3 int8s for values + 3 int64s for categories
+        assert cat.nbytes == exp
+
+    def test_memory_usage(self):
+        cat = Categorical([1, 2, 3])
+
+        # .categories is an index, so we include the hashtable
+        assert 0 < cat.nbytes <= cat.memory_usage()
+        assert 0 < cat.nbytes <= cat.memory_usage(deep=True)
+
+        cat = Categorical(["foo", "foo", "bar"])
+        assert cat.memory_usage(deep=True) > cat.nbytes
+
+        if not PYPY:
+            # sys.getsizeof will call the .memory_usage with
+            # deep=True, and add on some GC overhead
+            diff = cat.memory_usage(deep=True) - sys.getsizeof(cat)
+            assert abs(diff) < 100
+
+    def test_map(self):
+        c = Categorical(list("ABABC"), categories=list("CBA"), ordered=True)
+        result = c.map(lambda x: x.lower())
+        exp = Categorical(list("ababc"), categories=list("cba"), ordered=True)
+        tm.assert_categorical_equal(result, exp)
+
+        c = Categorical(list("ABABC"), categories=list("ABC"), ordered=False)
+        result = c.map(lambda x: x.lower())
+        exp = Categorical(list("ababc"), categories=list("abc"), ordered=False)
+        tm.assert_categorical_equal(result, exp)
+
+        result = c.map(lambda x: 1)
+        # GH 12766: Return an index not an array
+        tm.assert_index_equal(result, Index(np.array([1] * 5, dtype=np.int64)))
+
+    def test_validate_inplace(self):
+        cat = Categorical(["A", "B", "B", "C", "A"])
+        invalid_values = [1, "True", [1, 2, 3], 5.0]
+
+        for value in invalid_values:
+            with pytest.raises(ValueError):
+                cat.set_ordered(value=True, inplace=value)
+
+            with pytest.raises(ValueError):
+                cat.as_ordered(inplace=value)
+
+            with pytest.raises(ValueError):
+                cat.as_unordered(inplace=value)
+
+            with pytest.raises(ValueError):
+                cat.set_categories(["X", "Y", "Z"], rename=True, inplace=value)
+
+            with pytest.raises(ValueError):
+                cat.rename_categories(["X", "Y", "Z"], inplace=value)
+
+            with pytest.raises(ValueError):
+                cat.reorder_categories(["X", "Y", "Z"], ordered=True, inplace=value)
+
+            with pytest.raises(ValueError):
+                cat.add_categories(new_categories=["D", "E", "F"], inplace=value)
+
+            with pytest.raises(ValueError):
+                cat.remove_categories(removals=["D", "E", "F"], inplace=value)
+
+            with pytest.raises(ValueError):
+                cat.remove_unused_categories(inplace=value)
+
+            with pytest.raises(ValueError):
+                cat.sort_values(inplace=value)
+
+    def test_isna(self):
+        exp = np.array([False, False, True])
+        c = Categorical(["a", "b", np.nan])
+        res = c.isna()
+
+        tm.assert_numpy_array_equal(res, exp)

venv/lib/python3.6/site-packages/pandas/tests/arrays/categorical/test_api.py

@@ -0,0 +1,506 @@
+import numpy as np
+import pytest
+
+from pandas import Categorical, CategoricalIndex, DataFrame, Index, Series
+from pandas.core.arrays.categorical import _recode_for_categories
+from pandas.tests.arrays.categorical.common import TestCategorical
+import pandas.util.testing as tm
+
+
+class TestCategoricalAPI:
+    def test_ordered_api(self):
+        # GH 9347
+        cat1 = Categorical(list("acb"), ordered=False)
+        tm.assert_index_equal(cat1.categories, Index(["a", "b", "c"]))
+        assert not cat1.ordered
+
+        cat2 = Categorical(list("acb"), categories=list("bca"), ordered=False)
+        tm.assert_index_equal(cat2.categories, Index(["b", "c", "a"]))
+        assert not cat2.ordered
+
+        cat3 = Categorical(list("acb"), ordered=True)
+        tm.assert_index_equal(cat3.categories, Index(["a", "b", "c"]))
+        assert cat3.ordered
+
+        cat4 = Categorical(list("acb"), categories=list("bca"), ordered=True)
+        tm.assert_index_equal(cat4.categories, Index(["b", "c", "a"]))
+        assert cat4.ordered
+
+    def test_set_ordered(self):
+
+        cat = Categorical(["a", "b", "c", "a"], ordered=True)
+        cat2 = cat.as_unordered()
+        assert not cat2.ordered
+        cat2 = cat.as_ordered()
+        assert cat2.ordered
+        cat2.as_unordered(inplace=True)
+        assert not cat2.ordered
+        cat2.as_ordered(inplace=True)
+        assert cat2.ordered
+
+        assert cat2.set_ordered(True).ordered
+        assert not cat2.set_ordered(False).ordered
+        cat2.set_ordered(True, inplace=True)
+        assert cat2.ordered
+        cat2.set_ordered(False, inplace=True)
+        assert not cat2.ordered
+
+        # removed in 0.19.0
+        msg = "can't set attribute"
+        with pytest.raises(AttributeError, match=msg):
+            cat.ordered = True
+        with pytest.raises(AttributeError, match=msg):
+            cat.ordered = False
+
+    def test_rename_categories(self):
+        cat = Categorical(["a", "b", "c", "a"])
+
+        # inplace=False: the old one must not be changed
+        res = cat.rename_categories([1, 2, 3])
+        tm.assert_numpy_array_equal(
+            res.__array__(), np.array([1, 2, 3, 1], dtype=np.int64)
+        )
+        tm.assert_index_equal(res.categories, Index([1, 2, 3]))
+
+        exp_cat = np.array(["a", "b", "c", "a"], dtype=np.object_)
+        tm.assert_numpy_array_equal(cat.__array__(), exp_cat)
+
+        exp_cat = Index(["a", "b", "c"])
+        tm.assert_index_equal(cat.categories, exp_cat)
+
+        # GH18862 (let rename_categories take callables)
+        result = cat.rename_categories(lambda x: x.upper())
+        expected = Categorical(["A", "B", "C", "A"])
+        tm.assert_categorical_equal(result, expected)
+
+        # and now inplace
+        res = cat.rename_categories([1, 2, 3], inplace=True)
+        assert res is None
+        tm.assert_numpy_array_equal(
+            cat.__array__(), np.array([1, 2, 3, 1], dtype=np.int64)
+        )
+        tm.assert_index_equal(cat.categories, Index([1, 2, 3]))
+
+        # Lengthen
+        with pytest.raises(ValueError):
+            cat.rename_categories([1, 2, 3, 4])
+
+        # Shorten
+        with pytest.raises(ValueError):
+            cat.rename_categories([1, 2])
+
+    def test_rename_categories_series(self):
+        # https://github.com/pandas-dev/pandas/issues/17981
+        c = Categorical(["a", "b"])
+        result = c.rename_categories(Series([0, 1], index=["a", "b"]))
+        expected = Categorical([0, 1])
+        tm.assert_categorical_equal(result, expected)
+
+    def test_rename_categories_dict(self):
+        # GH 17336
+        cat = Categorical(["a", "b", "c", "d"])
+        res = cat.rename_categories({"a": 4, "b": 3, "c": 2, "d": 1})
+        expected = Index([4, 3, 2, 1])
+        tm.assert_index_equal(res.categories, expected)
+
+        # Test for inplace
+        res = cat.rename_categories({"a": 4, "b": 3, "c": 2, "d": 1}, inplace=True)
+        assert res is None
+        tm.assert_index_equal(cat.categories, expected)
+
+        # Test for dicts of smaller length
+        cat = Categorical(["a", "b", "c", "d"])
+        res = cat.rename_categories({"a": 1, "c": 3})
+
+        expected = Index([1, "b", 3, "d"])
+        tm.assert_index_equal(res.categories, expected)
+
+        # Test for dicts with bigger length
+        cat = Categorical(["a", "b", "c", "d"])
+        res = cat.rename_categories({"a": 1, "b": 2, "c": 3, "d": 4, "e": 5, "f": 6})
+        expected = Index([1, 2, 3, 4])
+        tm.assert_index_equal(res.categories, expected)
+
+        # Test for dicts with no items from old categories
+        cat = Categorical(["a", "b", "c", "d"])
+        res = cat.rename_categories({"f": 1, "g": 3})
+
+        expected = Index(["a", "b", "c", "d"])
+        tm.assert_index_equal(res.categories, expected)
+
+    def test_reorder_categories(self):
+        cat = Categorical(["a", "b", "c", "a"], ordered=True)
+        old = cat.copy()
+        new = Categorical(
+            ["a", "b", "c", "a"], categories=["c", "b", "a"], ordered=True
+        )
+
+        # first inplace == False
+        res = cat.reorder_categories(["c", "b", "a"])
+        # cat must be the same as before
+        tm.assert_categorical_equal(cat, old)
+        # only res is changed
+        tm.assert_categorical_equal(res, new)
+
+        # inplace == True
+        res = cat.reorder_categories(["c", "b", "a"], inplace=True)
+        assert res is None
+        tm.assert_categorical_equal(cat, new)
+
+        # not all "old" included in "new"
+        cat = Categorical(["a", "b", "c", "a"], ordered=True)
+
+        with pytest.raises(ValueError):
+            cat.reorder_categories(["a"])
+
+        # still not all "old" in "new"
+        with pytest.raises(ValueError):
+            cat.reorder_categories(["a", "b", "d"])
+
+        # all "old" included in "new", but too long
+        with pytest.raises(ValueError):
+            cat.reorder_categories(["a", "b", "c", "d"])
+
+    def test_add_categories(self):
+        cat = Categorical(["a", "b", "c", "a"], ordered=True)
+        old = cat.copy()
+        new = Categorical(
+            ["a", "b", "c", "a"], categories=["a", "b", "c", "d"], ordered=True
+        )
+
+        # first inplace == False
+        res = cat.add_categories("d")
+        tm.assert_categorical_equal(cat, old)
+        tm.assert_categorical_equal(res, new)
+
+        res = cat.add_categories(["d"])
+        tm.assert_categorical_equal(cat, old)
+        tm.assert_categorical_equal(res, new)
+
+        # inplace == True
+        res = cat.add_categories("d", inplace=True)
+        tm.assert_categorical_equal(cat, new)
+        assert res is None
+
+        # new is in old categories
+        with pytest.raises(ValueError):
+            cat.add_categories(["d"])
+
+        # GH 9927
+        cat = Categorical(list("abc"), ordered=True)
+        expected = Categorical(list("abc"), categories=list("abcde"), ordered=True)
+        # test with Series, np.array, index, list
+        res = cat.add_categories(Series(["d", "e"]))
+        tm.assert_categorical_equal(res, expected)
+        res = cat.add_categories(np.array(["d", "e"]))
+        tm.assert_categorical_equal(res, expected)
+        res = cat.add_categories(Index(["d", "e"]))
+        tm.assert_categorical_equal(res, expected)
+        res = cat.add_categories(["d", "e"])
+        tm.assert_categorical_equal(res, expected)
+
+    def test_set_categories(self):
+        cat = Categorical(["a", "b", "c", "a"], ordered=True)
+        exp_categories = Index(["c", "b", "a"])
+        exp_values = np.array(["a", "b", "c", "a"], dtype=np.object_)
+
+        res = cat.set_categories(["c", "b", "a"], inplace=True)
+        tm.assert_index_equal(cat.categories, exp_categories)
+        tm.assert_numpy_array_equal(cat.__array__(), exp_values)
+        assert res is None
+
+        res = cat.set_categories(["a", "b", "c"])
+        # cat must be the same as before
+        tm.assert_index_equal(cat.categories, exp_categories)
+        tm.assert_numpy_array_equal(cat.__array__(), exp_values)
+        # only res is changed
+        exp_categories_back = Index(["a", "b", "c"])
+        tm.assert_index_equal(res.categories, exp_categories_back)
+        tm.assert_numpy_array_equal(res.__array__(), exp_values)
+
+        # not all "old" included in "new" -> all not included ones are now
+        # np.nan
+        cat = Categorical(["a", "b", "c", "a"], ordered=True)
+        res = cat.set_categories(["a"])
+        tm.assert_numpy_array_equal(res.codes, np.array([0, -1, -1, 0], dtype=np.int8))
+
+        # still not all "old" in "new"
+        res = cat.set_categories(["a", "b", "d"])
+        tm.assert_numpy_array_equal(res.codes, np.array([0, 1, -1, 0], dtype=np.int8))
+        tm.assert_index_equal(res.categories, Index(["a", "b", "d"]))
+
+        # all "old" included in "new"
+        cat = cat.set_categories(["a", "b", "c", "d"])
+        exp_categories = Index(["a", "b", "c", "d"])
+        tm.assert_index_equal(cat.categories, exp_categories)
+
+        # internals...
+        c = Categorical([1, 2, 3, 4, 1], categories=[1, 2, 3, 4], ordered=True)
+        tm.assert_numpy_array_equal(c._codes, np.array([0, 1, 2, 3, 0], dtype=np.int8))
+        tm.assert_index_equal(c.categories, Index([1, 2, 3, 4]))
+
+        exp = np.array([1, 2, 3, 4, 1], dtype=np.int64)
+        tm.assert_numpy_array_equal(c.to_dense(), exp)
+
+        # all "pointers" to '4' must be changed from 3 to 0,...
+        c = c.set_categories([4, 3, 2, 1])
+
+        # positions are changed
+        tm.assert_numpy_array_equal(c._codes, np.array([3, 2, 1, 0, 3], dtype=np.int8))
+
+        # categories are now in new order
+        tm.assert_index_equal(c.categories, Index([4, 3, 2, 1]))
+
+        # output is the same
+        exp = np.array([1, 2, 3, 4, 1], dtype=np.int64)
+        tm.assert_numpy_array_equal(c.to_dense(), exp)
+        assert c.min() == 4
+        assert c.max() == 1
+
+        # set_categories should set the ordering if specified
+        c2 = c.set_categories([4, 3, 2, 1], ordered=False)
+        assert not c2.ordered
+
+        tm.assert_numpy_array_equal(c.to_dense(), c2.to_dense())
+
+        # set_categories should pass thru the ordering
+        c2 = c.set_ordered(False).set_categories([4, 3, 2, 1])
+        assert not c2.ordered
+
+        tm.assert_numpy_array_equal(c.to_dense(), c2.to_dense())
+
+    @pytest.mark.parametrize(
+        "values, categories, new_categories",
+        [
+            # No NaNs, same cats, same order
+            (["a", "b", "a"], ["a", "b"], ["a", "b"]),
+            # No NaNs, same cats, different order
+            (["a", "b", "a"], ["a", "b"], ["b", "a"]),
+            # Same, unsorted
+            (["b", "a", "a"], ["a", "b"], ["a", "b"]),
+            # No NaNs, same cats, different order
+            (["b", "a", "a"], ["a", "b"], ["b", "a"]),
+            # NaNs
+            (["a", "b", "c"], ["a", "b"], ["a", "b"]),
+            (["a", "b", "c"], ["a", "b"], ["b", "a"]),
+            (["b", "a", "c"], ["a", "b"], ["a", "b"]),
+            (["b", "a", "c"], ["a", "b"], ["a", "b"]),
+            # Introduce NaNs
+            (["a", "b", "c"], ["a", "b"], ["a"]),
+            (["a", "b", "c"], ["a", "b"], ["b"]),
+            (["b", "a", "c"], ["a", "b"], ["a"]),
+            (["b", "a", "c"], ["a", "b"], ["a"]),
+            # No overlap
+            (["a", "b", "c"], ["a", "b"], ["d", "e"]),
+        ],
+    )
+    @pytest.mark.parametrize("ordered", [True, False])
+    def test_set_categories_many(self, values, categories, new_categories, ordered):
+        c = Categorical(values, categories)
+        expected = Categorical(values, new_categories, ordered)
+        result = c.set_categories(new_categories, ordered=ordered)
+        tm.assert_categorical_equal(result, expected)
+
+    def test_set_categories_rename_less(self):
+        # GH 24675
+        cat = Categorical(["A", "B"])
+        result = cat.set_categories(["A"], rename=True)
+        expected = Categorical(["A", np.nan])
+        tm.assert_categorical_equal(result, expected)
+
+    def test_set_categories_private(self):
+        cat = Categorical(["a", "b", "c"], categories=["a", "b", "c", "d"])
+        cat._set_categories(["a", "c", "d", "e"])
+        expected = Categorical(["a", "c", "d"], categories=list("acde"))
+        tm.assert_categorical_equal(cat, expected)
+
+        # fastpath
+        cat = Categorical(["a", "b", "c"], categories=["a", "b", "c", "d"])
+        cat._set_categories(["a", "c", "d", "e"], fastpath=True)
+        expected = Categorical(["a", "c", "d"], categories=list("acde"))
+        tm.assert_categorical_equal(cat, expected)
+
+    def test_remove_categories(self):
+        cat = Categorical(["a", "b", "c", "a"], ordered=True)
+        old = cat.copy()
+        new = Categorical(["a", "b", np.nan, "a"], categories=["a", "b"], ordered=True)
+
+        # first inplace == False
+        res = cat.remove_categories("c")
+        tm.assert_categorical_equal(cat, old)
+        tm.assert_categorical_equal(res, new)
+
+        res = cat.remove_categories(["c"])
+        tm.assert_categorical_equal(cat, old)
+        tm.assert_categorical_equal(res, new)
+
+        # inplace == True
+        res = cat.remove_categories("c", inplace=True)
+        tm.assert_categorical_equal(cat, new)
+        assert res is None
+
+        # removal is not in categories
+        with pytest.raises(ValueError):
+            cat.remove_categories(["c"])
+
+    def test_remove_unused_categories(self):
+        c = Categorical(["a", "b", "c", "d", "a"], categories=["a", "b", "c", "d", "e"])
+        exp_categories_all = Index(["a", "b", "c", "d", "e"])
+        exp_categories_dropped = Index(["a", "b", "c", "d"])
+
+        tm.assert_index_equal(c.categories, exp_categories_all)
+
+        res = c.remove_unused_categories()
+        tm.assert_index_equal(res.categories, exp_categories_dropped)
+        tm.assert_index_equal(c.categories, exp_categories_all)
+
+        res = c.remove_unused_categories(inplace=True)
+        tm.assert_index_equal(c.categories, exp_categories_dropped)
+        assert res is None
+
+        # with NaN values (GH11599)
+        c = Categorical(["a", "b", "c", np.nan], categories=["a", "b", "c", "d", "e"])
+        res = c.remove_unused_categories()
+        tm.assert_index_equal(res.categories, Index(np.array(["a", "b", "c"])))
+        exp_codes = np.array([0, 1, 2, -1], dtype=np.int8)
+        tm.assert_numpy_array_equal(res.codes, exp_codes)
+        tm.assert_index_equal(c.categories, exp_categories_all)
+
+        val = ["F", np.nan, "D", "B", "D", "F", np.nan]
+        cat = Categorical(values=val, categories=list("ABCDEFG"))
+        out = cat.remove_unused_categories()
+        tm.assert_index_equal(out.categories, Index(["B", "D", "F"]))
+        exp_codes = np.array([2, -1, 1, 0, 1, 2, -1], dtype=np.int8)
+        tm.assert_numpy_array_equal(out.codes, exp_codes)
+        assert out.tolist() == val
+
+        alpha = list("abcdefghijklmnopqrstuvwxyz")
+        val = np.random.choice(alpha[::2], 10000).astype("object")
+        val[np.random.choice(len(val), 100)] = np.nan
+
+        cat = Categorical(values=val, categories=alpha)
+        out = cat.remove_unused_categories()
+        assert out.tolist() == val.tolist()
+
+
+class TestCategoricalAPIWithFactor(TestCategorical):
+    def test_describe(self):
+        # string type
+        desc = self.factor.describe()
+        assert self.factor.ordered
+        exp_index = CategoricalIndex(
+            ["a", "b", "c"], name="categories", ordered=self.factor.ordered
+        )
+        expected = DataFrame(
+            {"counts": [3, 2, 3], "freqs": [3 / 8.0, 2 / 8.0, 3 / 8.0]}, index=exp_index
+        )
+        tm.assert_frame_equal(desc, expected)
+
+        # check unused categories
+        cat = self.factor.copy()
+        cat.set_categories(["a", "b", "c", "d"], inplace=True)
+        desc = cat.describe()
+
+        exp_index = CategoricalIndex(
+            list("abcd"), ordered=self.factor.ordered, name="categories"
+        )
+        expected = DataFrame(
+            {"counts": [3, 2, 3, 0], "freqs": [3 / 8.0, 2 / 8.0, 3 / 8.0, 0]},
+            index=exp_index,
+        )
+        tm.assert_frame_equal(desc, expected)
+
+        # check an integer one
+        cat = Categorical([1, 2, 3, 1, 2, 3, 3, 2, 1, 1, 1])
+        desc = cat.describe()
+        exp_index = CategoricalIndex([1, 2, 3], ordered=cat.ordered, name="categories")
+        expected = DataFrame(
+            {"counts": [5, 3, 3], "freqs": [5 / 11.0, 3 / 11.0, 3 / 11.0]},
+            index=exp_index,
+        )
+        tm.assert_frame_equal(desc, expected)
+
+        # https://github.com/pandas-dev/pandas/issues/3678
+        # describe should work with NaN
+        cat = Categorical([np.nan, 1, 2, 2])
+        desc = cat.describe()
+        expected = DataFrame(
+            {"counts": [1, 2, 1], "freqs": [1 / 4.0, 2 / 4.0, 1 / 4.0]},
+            index=CategoricalIndex(
+                [1, 2, np.nan], categories=[1, 2], name="categories"
+            ),
+        )
+        tm.assert_frame_equal(desc, expected)
+
+    def test_set_categories_inplace(self):
+        cat = self.factor.copy()
+        cat.set_categories(["a", "b", "c", "d"], inplace=True)
+        tm.assert_index_equal(cat.categories, Index(["a", "b", "c", "d"]))
+
+
+class TestPrivateCategoricalAPI:
+    def test_codes_immutable(self):
+
+        # Codes should be read only
+        c = Categorical(["a", "b", "c", "a", np.nan])
+        exp = np.array([0, 1, 2, 0, -1], dtype="int8")
+        tm.assert_numpy_array_equal(c.codes, exp)
+
+        # Assignments to codes should raise
+        with pytest.raises(ValueError):
+            c.codes = np.array([0, 1, 2, 0, 1], dtype="int8")
+
+        # changes in the codes array should raise
+        codes = c.codes
+
+        with pytest.raises(ValueError):
+            codes[4] = 1
+
+        # But even after getting the codes, the original array should still be
+        # writeable!
+        c[4] = "a"
+        exp = np.array([0, 1, 2, 0, 0], dtype="int8")
+        tm.assert_numpy_array_equal(c.codes, exp)
+        c._codes[4] = 2
+        exp = np.array([0, 1, 2, 0, 2], dtype="int8")
+        tm.assert_numpy_array_equal(c.codes, exp)
+
+    @pytest.mark.parametrize(
+        "codes, old, new, expected",
+        [
+            ([0, 1], ["a", "b"], ["a", "b"], [0, 1]),
+            ([0, 1], ["b", "a"], ["b", "a"], [0, 1]),
+            ([0, 1], ["a", "b"], ["b", "a"], [1, 0]),
+            ([0, 1], ["b", "a"], ["a", "b"], [1, 0]),
+            ([0, 1, 0, 1], ["a", "b"], ["a", "b", "c"], [0, 1, 0, 1]),
+            ([0, 1, 2, 2], ["a", "b", "c"], ["a", "b"], [0, 1, -1, -1]),
+            ([0, 1, -1], ["a", "b", "c"], ["a", "b", "c"], [0, 1, -1]),
+            ([0, 1, -1], ["a", "b", "c"], ["b"], [-1, 0, -1]),
+            ([0, 1, -1], ["a", "b", "c"], ["d"], [-1, -1, -1]),
+            ([0, 1, -1], ["a", "b", "c"], [], [-1, -1, -1]),
+            ([-1, -1], [], ["a", "b"], [-1, -1]),
+            ([1, 0], ["b", "a"], ["a", "b"], [0, 1]),
+        ],
+    )
+    def test_recode_to_categories(self, codes, old, new, expected):
+        codes = np.asanyarray(codes, dtype=np.int8)
+        expected = np.asanyarray(expected, dtype=np.int8)
+        old = Index(old)
+        new = Index(new)
+        result = _recode_for_categories(codes, old, new)
+        tm.assert_numpy_array_equal(result, expected)
+
+    def test_recode_to_categories_large(self):
+        N = 1000
+        codes = np.arange(N)
+        old = Index(codes)
+        expected = np.arange(N - 1, -1, -1, dtype=np.int16)
+        new = Index(expected)
+        result = _recode_for_categories(codes, old, new)
+        tm.assert_numpy_array_equal(result, expected)
+
+    def test_deprecated_get_values(self):
+        cat = Categorical(["a", "b", "c", "a"])
+        with tm.assert_produces_warning(FutureWarning):
+            res = cat.get_values()
+        tm.assert_numpy_array_equal(res, np.array(cat))

venv/lib/python3.6/site-packages/pandas/tests/arrays/categorical/test_constructors.py

@@ -0,0 +1,603 @@
+from datetime import datetime
+
+import numpy as np
+import pytest
+
+from pandas.core.dtypes.common import is_float_dtype, is_integer_dtype
+from pandas.core.dtypes.dtypes import CategoricalDtype
+
+import pandas as pd
+from pandas import (
+    Categorical,
+    CategoricalIndex,
+    DatetimeIndex,
+    Index,
+    Interval,
+    IntervalIndex,
+    NaT,
+    Series,
+    Timestamp,
+    date_range,
+    period_range,
+    timedelta_range,
+)
+import pandas.util.testing as tm
+
+
+class TestCategoricalConstructors:
+    def test_validate_ordered(self):
+        # see gh-14058
+        exp_msg = "'ordered' must either be 'True' or 'False'"
+        exp_err = TypeError
+
+        # This should be a boolean.
+        ordered = np.array([0, 1, 2])
+
+        with pytest.raises(exp_err, match=exp_msg):
+            Categorical([1, 2, 3], ordered=ordered)
+
+        with pytest.raises(exp_err, match=exp_msg):
+            Categorical.from_codes(
+                [0, 0, 1], categories=["a", "b", "c"], ordered=ordered
+            )
+
+    def test_constructor_empty(self):
+        # GH 17248
+        c = Categorical([])
+        expected = Index([])
+        tm.assert_index_equal(c.categories, expected)
+
+        c = Categorical([], categories=[1, 2, 3])
+        expected = pd.Int64Index([1, 2, 3])
+        tm.assert_index_equal(c.categories, expected)
+
+    def test_constructor_empty_boolean(self):
+        # see gh-22702
+        cat = pd.Categorical([], categories=[True, False])
+        categories = sorted(cat.categories.tolist())
+        assert categories == [False, True]
+
+    def test_constructor_tuples(self):
+        values = np.array([(1,), (1, 2), (1,), (1, 2)], dtype=object)
+        result = Categorical(values)
+        expected = Index([(1,), (1, 2)], tupleize_cols=False)
+        tm.assert_index_equal(result.categories, expected)
+        assert result.ordered is False
+
+    def test_constructor_tuples_datetimes(self):
+        # numpy will auto reshape when all of the tuples are the
+        # same len, so add an extra one with 2 items and slice it off
+        values = np.array(
+            [
+                (Timestamp("2010-01-01"),),
+                (Timestamp("2010-01-02"),),
+                (Timestamp("2010-01-01"),),
+                (Timestamp("2010-01-02"),),
+                ("a", "b"),
+            ],
+            dtype=object,
+        )[:-1]
+        result = Categorical(values)
+        expected = Index(
+            [(Timestamp("2010-01-01"),), (Timestamp("2010-01-02"),)],
+            tupleize_cols=False,
+        )
+        tm.assert_index_equal(result.categories, expected)
+
+    def test_constructor_unsortable(self):
+
+        # it works!
+        arr = np.array([1, 2, 3, datetime.now()], dtype="O")
+        factor = Categorical(arr, ordered=False)
+        assert not factor.ordered
+
+        # this however will raise as cannot be sorted
+        msg = (
+            "'values' is not ordered, please explicitly specify the "
+            "categories order by passing in a categories argument."
+        )
+        with pytest.raises(TypeError, match=msg):
+            Categorical(arr, ordered=True)
+
+    def test_constructor_interval(self):
+        result = Categorical(
+            [Interval(1, 2), Interval(2, 3), Interval(3, 6)], ordered=True
+        )
+        ii = IntervalIndex([Interval(1, 2), Interval(2, 3), Interval(3, 6)])
+        exp = Categorical(ii, ordered=True)
+        tm.assert_categorical_equal(result, exp)
+        tm.assert_index_equal(result.categories, ii)
+
+    def test_constructor(self):
+
+        exp_arr = np.array(["a", "b", "c", "a", "b", "c"], dtype=np.object_)
+        c1 = Categorical(exp_arr)
+        tm.assert_numpy_array_equal(c1.__array__(), exp_arr)
+        c2 = Categorical(exp_arr, categories=["a", "b", "c"])
+        tm.assert_numpy_array_equal(c2.__array__(), exp_arr)
+        c2 = Categorical(exp_arr, categories=["c", "b", "a"])
+        tm.assert_numpy_array_equal(c2.__array__(), exp_arr)
+
+        # categories must be unique
+        msg = "Categorical categories must be unique"
+        with pytest.raises(ValueError, match=msg):
+            Categorical([1, 2], [1, 2, 2])
+
+        with pytest.raises(ValueError, match=msg):
+            Categorical(["a", "b"], ["a", "b", "b"])
+
+        # The default should be unordered
+        c1 = Categorical(["a", "b", "c", "a"])
+        assert not c1.ordered
+
+        # Categorical as input
+        c1 = Categorical(["a", "b", "c", "a"])
+        c2 = Categorical(c1)
+        tm.assert_categorical_equal(c1, c2)
+
+        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "b", "c", "d"])
+        c2 = Categorical(c1)
+        tm.assert_categorical_equal(c1, c2)
+
+        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "c", "b"])
+        c2 = Categorical(c1)
+        tm.assert_categorical_equal(c1, c2)
+
+        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "c", "b"])
+        c2 = Categorical(c1, categories=["a", "b", "c"])
+        tm.assert_numpy_array_equal(c1.__array__(), c2.__array__())
+        tm.assert_index_equal(c2.categories, Index(["a", "b", "c"]))
+
+        # Series of dtype category
+        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "b", "c", "d"])
+        c2 = Categorical(Series(c1))
+        tm.assert_categorical_equal(c1, c2)
+
+        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "c", "b"])
+        c2 = Categorical(Series(c1))
+        tm.assert_categorical_equal(c1, c2)
+
+        # Series
+        c1 = Categorical(["a", "b", "c", "a"])
+        c2 = Categorical(Series(["a", "b", "c", "a"]))
+        tm.assert_categorical_equal(c1, c2)
+
+        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "b", "c", "d"])
+        c2 = Categorical(Series(["a", "b", "c", "a"]), categories=["a", "b", "c", "d"])
+        tm.assert_categorical_equal(c1, c2)
+
+        # This should result in integer categories, not float!
+        cat = Categorical([1, 2, 3, np.nan], categories=[1, 2, 3])
+        assert is_integer_dtype(cat.categories)
+
+        # https://github.com/pandas-dev/pandas/issues/3678
+        cat = Categorical([np.nan, 1, 2, 3])
+        assert is_integer_dtype(cat.categories)
+
+        # this should result in floats
+        cat = Categorical([np.nan, 1, 2.0, 3])
+        assert is_float_dtype(cat.categories)
+
+        cat = Categorical([np.nan, 1.0, 2.0, 3.0])
+        assert is_float_dtype(cat.categories)
+
+        # This doesn't work -> this would probably need some kind of "remember
+        # the original type" feature to try to cast the array interface result
+        # to...
+
+        # vals = np.asarray(cat[cat.notna()])
+        # assert is_integer_dtype(vals)
+
+        # corner cases
+        cat = Categorical([1])
+        assert len(cat.categories) == 1
+        assert cat.categories[0] == 1
+        assert len(cat.codes) == 1
+        assert cat.codes[0] == 0
+
+        cat = Categorical(["a"])
+        assert len(cat.categories) == 1
+        assert cat.categories[0] == "a"
+        assert len(cat.codes) == 1
+        assert cat.codes[0] == 0
+
+        # Scalars should be converted to lists
+        cat = Categorical(1)
+        assert len(cat.categories) == 1
+        assert cat.categories[0] == 1
+        assert len(cat.codes) == 1
+        assert cat.codes[0] == 0
+
+        # two arrays
+        #  - when the first is an integer dtype and the second is not
+        #  - when the resulting codes are all -1/NaN
+        with tm.assert_produces_warning(None):
+            c_old = Categorical([0, 1, 2, 0, 1, 2], categories=["a", "b", "c"])  # noqa
+
+        with tm.assert_produces_warning(None):
+            c_old = Categorical([0, 1, 2, 0, 1, 2], categories=[3, 4, 5])  # noqa
+
+        # the next one are from the old docs
+        with tm.assert_produces_warning(None):
+            c_old2 = Categorical([0, 1, 2, 0, 1, 2], [1, 2, 3])  # noqa
+            cat = Categorical([1, 2], categories=[1, 2, 3])
+
+        # this is a legitimate constructor
+        with tm.assert_produces_warning(None):
+            c = Categorical(  # noqa
+                np.array([], dtype="int64"), categories=[3, 2, 1], ordered=True
+            )
+
+    def test_constructor_with_existing_categories(self):
+        # GH25318: constructing with pd.Series used to bogusly skip recoding
+        # categories
+        c0 = Categorical(["a", "b", "c", "a"])
+        c1 = Categorical(["a", "b", "c", "a"], categories=["b", "c"])
+
+        c2 = Categorical(c0, categories=c1.categories)
+        tm.assert_categorical_equal(c1, c2)
+
+        c3 = Categorical(Series(c0), categories=c1.categories)
+        tm.assert_categorical_equal(c1, c3)
+
+    def test_constructor_not_sequence(self):
+        # https://github.com/pandas-dev/pandas/issues/16022
+        msg = r"^Parameter 'categories' must be list-like, was"
+        with pytest.raises(TypeError, match=msg):
+            Categorical(["a", "b"], categories="a")
+
+    def test_constructor_with_null(self):
+
+        # Cannot have NaN in categories
+        msg = "Categorial categories cannot be null"
+        with pytest.raises(ValueError, match=msg):
+            Categorical([np.nan, "a", "b", "c"], categories=[np.nan, "a", "b", "c"])
+
+        with pytest.raises(ValueError, match=msg):
+            Categorical([None, "a", "b", "c"], categories=[None, "a", "b", "c"])
+
+        with pytest.raises(ValueError, match=msg):
+            Categorical(
+                DatetimeIndex(["nat", "20160101"]),
+                categories=[NaT, Timestamp("20160101")],
+            )
+
+    def test_constructor_with_index(self):
+        ci = CategoricalIndex(list("aabbca"), categories=list("cab"))
+        tm.assert_categorical_equal(ci.values, Categorical(ci))
+
+        ci = CategoricalIndex(list("aabbca"), categories=list("cab"))
+        tm.assert_categorical_equal(
+            ci.values, Categorical(ci.astype(object), categories=ci.categories)
+        )
+
+    def test_constructor_with_generator(self):
+        # This was raising an Error in isna(single_val).any() because isna
+        # returned a scalar for a generator
+        xrange = range
+
+        exp = Categorical([0, 1, 2])
+        cat = Categorical((x for x in [0, 1, 2]))
+        tm.assert_categorical_equal(cat, exp)
+        cat = Categorical(xrange(3))
+        tm.assert_categorical_equal(cat, exp)
+
+        # This uses xrange internally
+        from pandas.core.index import MultiIndex
+
+        MultiIndex.from_product([range(5), ["a", "b", "c"]])
+
+        # check that categories accept generators and sequences
+        cat = Categorical([0, 1, 2], categories=(x for x in [0, 1, 2]))
+        tm.assert_categorical_equal(cat, exp)
+        cat = Categorical([0, 1, 2], categories=xrange(3))
+        tm.assert_categorical_equal(cat, exp)
+
+    @pytest.mark.parametrize(
+        "dtl",
+        [
+            date_range("1995-01-01 00:00:00", periods=5, freq="s"),
+            date_range("1995-01-01 00:00:00", periods=5, freq="s", tz="US/Eastern"),
+            timedelta_range("1 day", periods=5, freq="s"),
+        ],
+    )
+    def test_constructor_with_datetimelike(self, dtl):
+        # see gh-12077
+        # constructor with a datetimelike and NaT
+
+        s = Series(dtl)
+        c = Categorical(s)
+
+        expected = type(dtl)(s)
+        expected.freq = None
+
+        tm.assert_index_equal(c.categories, expected)
+        tm.assert_numpy_array_equal(c.codes, np.arange(5, dtype="int8"))
+
+        # with NaT
+        s2 = s.copy()
+        s2.iloc[-1] = NaT
+        c = Categorical(s2)
+
+        expected = type(dtl)(s2.dropna())
+        expected.freq = None
+
+        tm.assert_index_equal(c.categories, expected)
+
+        exp = np.array([0, 1, 2, 3, -1], dtype=np.int8)
+        tm.assert_numpy_array_equal(c.codes, exp)
+
+        result = repr(c)
+        assert "NaT" in result
+
+    def test_constructor_from_index_series_datetimetz(self):
+        idx = date_range("2015-01-01 10:00", freq="D", periods=3, tz="US/Eastern")
+        result = Categorical(idx)
+        tm.assert_index_equal(result.categories, idx)
+
+        result = Categorical(Series(idx))
+        tm.assert_index_equal(result.categories, idx)
+
+    def test_constructor_from_index_series_timedelta(self):
+        idx = timedelta_range("1 days", freq="D", periods=3)
+        result = Categorical(idx)
+        tm.assert_index_equal(result.categories, idx)
+
+        result = Categorical(Series(idx))
+        tm.assert_index_equal(result.categories, idx)
+
+    def test_constructor_from_index_series_period(self):
+        idx = period_range("2015-01-01", freq="D", periods=3)
+        result = Categorical(idx)
+        tm.assert_index_equal(result.categories, idx)
+
+        result = Categorical(Series(idx))
+        tm.assert_index_equal(result.categories, idx)
+
+    def test_constructor_invariant(self):
+        # GH 14190
+        vals = [
+            np.array([1.0, 1.2, 1.8, np.nan]),
+            np.array([1, 2, 3], dtype="int64"),
+            ["a", "b", "c", np.nan],
+            [pd.Period("2014-01"), pd.Period("2014-02"), NaT],
+            [Timestamp("2014-01-01"), Timestamp("2014-01-02"), NaT],
+            [
+                Timestamp("2014-01-01", tz="US/Eastern"),
+                Timestamp("2014-01-02", tz="US/Eastern"),
+                NaT,
+            ],
+        ]
+        for val in vals:
+            c = Categorical(val)
+            c2 = Categorical(c)
+            tm.assert_categorical_equal(c, c2)
+
+    @pytest.mark.parametrize("ordered", [True, False])
+    def test_constructor_with_dtype(self, ordered):
+        categories = ["b", "a", "c"]
+        dtype = CategoricalDtype(categories, ordered=ordered)
+        result = Categorical(["a", "b", "a", "c"], dtype=dtype)
+        expected = Categorical(
+            ["a", "b", "a", "c"], categories=categories, ordered=ordered
+        )
+        tm.assert_categorical_equal(result, expected)
+        assert result.ordered is ordered
+
+    def test_constructor_dtype_and_others_raises(self):
+        dtype = CategoricalDtype(["a", "b"], ordered=True)
+        msg = "Cannot specify `categories` or `ordered` together with `dtype`."
+        with pytest.raises(ValueError, match=msg):
+            Categorical(["a", "b"], categories=["a", "b"], dtype=dtype)
+
+        with pytest.raises(ValueError, match=msg):
+            Categorical(["a", "b"], ordered=True, dtype=dtype)
+
+        with pytest.raises(ValueError, match=msg):
+            Categorical(["a", "b"], ordered=False, dtype=dtype)
+
+    @pytest.mark.parametrize("categories", [None, ["a", "b"], ["a", "c"]])
+    @pytest.mark.parametrize("ordered", [True, False])
+    def test_constructor_str_category(self, categories, ordered):
+        result = Categorical(
+            ["a", "b"], categories=categories, ordered=ordered, dtype="category"
+        )
+        expected = Categorical(["a", "b"], categories=categories, ordered=ordered)
+        tm.assert_categorical_equal(result, expected)
+
+    def test_constructor_str_unknown(self):
+        with pytest.raises(ValueError, match="Unknown dtype"):
+            Categorical([1, 2], dtype="foo")
+
+    def test_constructor_from_categorical_with_dtype(self):
+        dtype = CategoricalDtype(["a", "b", "c"], ordered=True)
+        values = Categorical(["a", "b", "d"])
+        result = Categorical(values, dtype=dtype)
+        # We use dtype.categories, not values.categories
+        expected = Categorical(
+            ["a", "b", "d"], categories=["a", "b", "c"], ordered=True
+        )
+        tm.assert_categorical_equal(result, expected)
+
+    def test_constructor_from_categorical_with_unknown_dtype(self):
+        dtype = CategoricalDtype(None, ordered=True)
+        values = Categorical(["a", "b", "d"])
+        result = Categorical(values, dtype=dtype)
+        # We use values.categories, not dtype.categories
+        expected = Categorical(
+            ["a", "b", "d"], categories=["a", "b", "d"], ordered=True
+        )
+        tm.assert_categorical_equal(result, expected)
+
+    def test_constructor_from_categorical_string(self):
+        values = Categorical(["a", "b", "d"])
+        # use categories, ordered
+        result = Categorical(
+            values, categories=["a", "b", "c"], ordered=True, dtype="category"
+        )
+        expected = Categorical(
+            ["a", "b", "d"], categories=["a", "b", "c"], ordered=True
+        )
+        tm.assert_categorical_equal(result, expected)
+
+        # No string
+        result = Categorical(values, categories=["a", "b", "c"], ordered=True)
+        tm.assert_categorical_equal(result, expected)
+
+    def test_constructor_with_categorical_categories(self):
+        # GH17884
+        expected = Categorical(["a", "b"], categories=["a", "b", "c"])
+
+        result = Categorical(["a", "b"], categories=Categorical(["a", "b", "c"]))
+        tm.assert_categorical_equal(result, expected)
+
+        result = Categorical(["a", "b"], categories=CategoricalIndex(["a", "b", "c"]))
+        tm.assert_categorical_equal(result, expected)
+
+    def test_from_codes(self):
+
+        # too few categories
+        dtype = CategoricalDtype(categories=[1, 2])
+        msg = "codes need to be between "
+        with pytest.raises(ValueError, match=msg):
+            Categorical.from_codes([1, 2], categories=dtype.categories)
+        with pytest.raises(ValueError, match=msg):
+            Categorical.from_codes([1, 2], dtype=dtype)
+
+        # no int codes
+        msg = "codes need to be array-like integers"
+        with pytest.raises(ValueError, match=msg):
+            Categorical.from_codes(["a"], categories=dtype.categories)
+        with pytest.raises(ValueError, match=msg):
+            Categorical.from_codes(["a"], dtype=dtype)
+
+        # no unique categories
+        with pytest.raises(ValueError, match="Categorical categories must be unique"):
+            Categorical.from_codes([0, 1, 2], categories=["a", "a", "b"])
+
+        # NaN categories included
+        with pytest.raises(ValueError, match="Categorial categories cannot be null"):
+            Categorical.from_codes([0, 1, 2], categories=["a", "b", np.nan])
+
+        # too negative
+        dtype = CategoricalDtype(categories=["a", "b", "c"])
+        msg = r"codes need to be between -1 and len\(categories\)-1"
+        with pytest.raises(ValueError, match=msg):
+            Categorical.from_codes([-2, 1, 2], categories=dtype.categories)
+        with pytest.raises(ValueError, match=msg):
+            Categorical.from_codes([-2, 1, 2], dtype=dtype)
+
+        exp = Categorical(["a", "b", "c"], ordered=False)
+        res = Categorical.from_codes([0, 1, 2], categories=dtype.categories)
+        tm.assert_categorical_equal(exp, res)
+
+        res = Categorical.from_codes([0, 1, 2], dtype=dtype)
+        tm.assert_categorical_equal(exp, res)
+
+    def test_from_codes_with_categorical_categories(self):
+        # GH17884
+        expected = Categorical(["a", "b"], categories=["a", "b", "c"])
+
+        result = Categorical.from_codes([0, 1], categories=Categorical(["a", "b", "c"]))
+        tm.assert_categorical_equal(result, expected)
+
+        result = Categorical.from_codes(
+            [0, 1], categories=CategoricalIndex(["a", "b", "c"])
+        )
+        tm.assert_categorical_equal(result, expected)
+
+        # non-unique Categorical still raises
+        with pytest.raises(ValueError, match="Categorical categories must be unique"):
+            Categorical.from_codes([0, 1], Categorical(["a", "b", "a"]))
+
+    def test_from_codes_with_nan_code(self):
+        # GH21767
+        codes = [1, 2, np.nan]
+        dtype = CategoricalDtype(categories=["a", "b", "c"])
+        with pytest.raises(ValueError, match="codes need to be array-like integers"):
+            Categorical.from_codes(codes, categories=dtype.categories)
+        with pytest.raises(ValueError, match="codes need to be array-like integers"):
+            Categorical.from_codes(codes, dtype=dtype)
+
+    def test_from_codes_with_float(self):
+        # GH21767
+        codes = [1.0, 2.0, 0]  # integer, but in float dtype
+        dtype = CategoricalDtype(categories=["a", "b", "c"])
+
+        with tm.assert_produces_warning(FutureWarning):
+            cat = Categorical.from_codes(codes, dtype.categories)
+        tm.assert_numpy_array_equal(cat.codes, np.array([1, 2, 0], dtype="i1"))
+
+        with tm.assert_produces_warning(FutureWarning):
+            cat = Categorical.from_codes(codes, dtype=dtype)
+        tm.assert_numpy_array_equal(cat.codes, np.array([1, 2, 0], dtype="i1"))
+
+        codes = [1.1, 2.0, 0]  # non-integer
+        with pytest.raises(ValueError, match="codes need to be array-like integers"):
+            Categorical.from_codes(codes, dtype.categories)
+        with pytest.raises(ValueError, match="codes need to be array-like integers"):
+            Categorical.from_codes(codes, dtype=dtype)
+
+    def test_from_codes_with_dtype_raises(self):
+        msg = "Cannot specify"
+        with pytest.raises(ValueError, match=msg):
+            Categorical.from_codes(
+                [0, 1], categories=["a", "b"], dtype=CategoricalDtype(["a", "b"])
+            )
+
+        with pytest.raises(ValueError, match=msg):
+            Categorical.from_codes(
+                [0, 1], ordered=True, dtype=CategoricalDtype(["a", "b"])
+            )
+
+    def test_from_codes_neither(self):
+        msg = "Both were None"
+        with pytest.raises(ValueError, match=msg):
+            Categorical.from_codes([0, 1])
+
+    @pytest.mark.parametrize("dtype", [None, "category"])
+    def test_from_inferred_categories(self, dtype):
+        cats = ["a", "b"]
+        codes = np.array([0, 0, 1, 1], dtype="i8")
+        result = Categorical._from_inferred_categories(cats, codes, dtype)
+        expected = Categorical.from_codes(codes, cats)
+        tm.assert_categorical_equal(result, expected)
+
+    @pytest.mark.parametrize("dtype", [None, "category"])
+    def test_from_inferred_categories_sorts(self, dtype):
+        cats = ["b", "a"]
+        codes = np.array([0, 1, 1, 1], dtype="i8")
+        result = Categorical._from_inferred_categories(cats, codes, dtype)
+        expected = Categorical.from_codes([1, 0, 0, 0], ["a", "b"])
+        tm.assert_categorical_equal(result, expected)
+
+    def test_from_inferred_categories_dtype(self):
+        cats = ["a", "b", "d"]
+        codes = np.array([0, 1, 0, 2], dtype="i8")
+        dtype = CategoricalDtype(["c", "b", "a"], ordered=True)
+        result = Categorical._from_inferred_categories(cats, codes, dtype)
+        expected = Categorical(
+            ["a", "b", "a", "d"], categories=["c", "b", "a"], ordered=True
+        )
+        tm.assert_categorical_equal(result, expected)
+
+    def test_from_inferred_categories_coerces(self):
+        cats = ["1", "2", "bad"]
+        codes = np.array([0, 0, 1, 2], dtype="i8")
+        dtype = CategoricalDtype([1, 2])
+        result = Categorical._from_inferred_categories(cats, codes, dtype)
+        expected = Categorical([1, 1, 2, np.nan])
+        tm.assert_categorical_equal(result, expected)
+
+    @pytest.mark.parametrize("ordered", [None, True, False])
+    def test_construction_with_ordered(self, ordered):
+        # GH 9347, 9190
+        cat = Categorical([0, 1, 2], ordered=ordered)
+        assert cat.ordered == bool(ordered)
+
+    @pytest.mark.xfail(reason="Imaginary values not supported in Categorical")
+    def test_constructor_imaginary(self):
+        values = [1, 2, 3 + 1j]
+        c1 = Categorical(values)
+        tm.assert_index_equal(c1.categories, Index(values))
+        tm.assert_numpy_array_equal(np.array(c1), np.array(values))

venv/lib/python3.6/site-packages/pandas/tests/arrays/categorical/test_dtypes.py

@@ -0,0 +1,181 @@
+import numpy as np
+import pytest
+
+from pandas.core.dtypes.dtypes import CategoricalDtype
+
+from pandas import Categorical, CategoricalIndex, Index, Series, Timestamp
+import pandas.util.testing as tm
+
+
+class TestCategoricalDtypes:
+    def test_is_equal_dtype(self):
+
+        # test dtype comparisons between cats
+
+        c1 = Categorical(list("aabca"), categories=list("abc"), ordered=False)
+        c2 = Categorical(list("aabca"), categories=list("cab"), ordered=False)
+        c3 = Categorical(list("aabca"), categories=list("cab"), ordered=True)
+        assert c1.is_dtype_equal(c1)
+        assert c2.is_dtype_equal(c2)
+        assert c3.is_dtype_equal(c3)
+        assert c1.is_dtype_equal(c2)
+        assert not c1.is_dtype_equal(c3)
+        assert not c1.is_dtype_equal(Index(list("aabca")))
+        assert not c1.is_dtype_equal(c1.astype(object))
+        assert c1.is_dtype_equal(CategoricalIndex(c1))
+        assert c1.is_dtype_equal(CategoricalIndex(c1, categories=list("cab")))
+        assert not c1.is_dtype_equal(CategoricalIndex(c1, ordered=True))
+
+        # GH 16659
+        s1 = Series(c1)
+        s2 = Series(c2)
+        s3 = Series(c3)
+        assert c1.is_dtype_equal(s1)
+        assert c2.is_dtype_equal(s2)
+        assert c3.is_dtype_equal(s3)
+        assert c1.is_dtype_equal(s2)
+        assert not c1.is_dtype_equal(s3)
+        assert not c1.is_dtype_equal(s1.astype(object))
+
+    def test_set_dtype_same(self):
+        c = Categorical(["a", "b", "c"])
+        result = c._set_dtype(CategoricalDtype(["a", "b", "c"]))
+        tm.assert_categorical_equal(result, c)
+
+    def test_set_dtype_new_categories(self):
+        c = Categorical(["a", "b", "c"])
+        result = c._set_dtype(CategoricalDtype(list("abcd")))
+        tm.assert_numpy_array_equal(result.codes, c.codes)
+        tm.assert_index_equal(result.dtype.categories, Index(list("abcd")))
+
+    @pytest.mark.parametrize(
+        "values, categories, new_categories",
+        [
+            # No NaNs, same cats, same order
+            (["a", "b", "a"], ["a", "b"], ["a", "b"]),
+            # No NaNs, same cats, different order
+            (["a", "b", "a"], ["a", "b"], ["b", "a"]),
+            # Same, unsorted
+            (["b", "a", "a"], ["a", "b"], ["a", "b"]),
+            # No NaNs, same cats, different order
+            (["b", "a", "a"], ["a", "b"], ["b", "a"]),
+            # NaNs
+            (["a", "b", "c"], ["a", "b"], ["a", "b"]),
+            (["a", "b", "c"], ["a", "b"], ["b", "a"]),
+            (["b", "a", "c"], ["a", "b"], ["a", "b"]),
+            (["b", "a", "c"], ["a", "b"], ["a", "b"]),
+            # Introduce NaNs
+            (["a", "b", "c"], ["a", "b"], ["a"]),
+            (["a", "b", "c"], ["a", "b"], ["b"]),
+            (["b", "a", "c"], ["a", "b"], ["a"]),
+            (["b", "a", "c"], ["a", "b"], ["a"]),
+            # No overlap
+            (["a", "b", "c"], ["a", "b"], ["d", "e"]),
+        ],
+    )
+    @pytest.mark.parametrize("ordered", [True, False])
+    def test_set_dtype_many(self, values, categories, new_categories, ordered):
+        c = Categorical(values, categories)
+        expected = Categorical(values, new_categories, ordered)
+        result = c._set_dtype(expected.dtype)
+        tm.assert_categorical_equal(result, expected)
+
+    def test_set_dtype_no_overlap(self):
+        c = Categorical(["a", "b", "c"], ["d", "e"])
+        result = c._set_dtype(CategoricalDtype(["a", "b"]))
+        expected = Categorical([None, None, None], categories=["a", "b"])
+        tm.assert_categorical_equal(result, expected)
+
+    def test_codes_dtypes(self):
+
+        # GH 8453
+        result = Categorical(["foo", "bar", "baz"])
+        assert result.codes.dtype == "int8"
+
+        result = Categorical(["foo{i:05d}".format(i=i) for i in range(400)])
+        assert result.codes.dtype == "int16"
+
+        result = Categorical(["foo{i:05d}".format(i=i) for i in range(40000)])
+        assert result.codes.dtype == "int32"
+
+        # adding cats
+        result = Categorical(["foo", "bar", "baz"])
+        assert result.codes.dtype == "int8"
+        result = result.add_categories(["foo{i:05d}".format(i=i) for i in range(400)])
+        assert result.codes.dtype == "int16"
+
+        # removing cats
+        result = result.remove_categories(
+            ["foo{i:05d}".format(i=i) for i in range(300)]
+        )
+        assert result.codes.dtype == "int8"
+
+    @pytest.mark.parametrize("ordered", [True, False])
+    def test_astype(self, ordered):
+        # string
+        cat = Categorical(list("abbaaccc"), ordered=ordered)
+        result = cat.astype(object)
+        expected = np.array(cat)
+        tm.assert_numpy_array_equal(result, expected)
+
+        msg = "could not convert string to float"
+        with pytest.raises(ValueError, match=msg):
+            cat.astype(float)
+
+        # numeric
+        cat = Categorical([0, 1, 2, 2, 1, 0, 1, 0, 2], ordered=ordered)
+        result = cat.astype(object)
+        expected = np.array(cat, dtype=object)
+        tm.assert_numpy_array_equal(result, expected)
+
+        result = cat.astype(int)
+        expected = np.array(cat, dtype=np.int)
+        tm.assert_numpy_array_equal(result, expected)
+
+        result = cat.astype(float)
+        expected = np.array(cat, dtype=np.float)
+        tm.assert_numpy_array_equal(result, expected)
+
+    @pytest.mark.parametrize("dtype_ordered", [True, False])
+    @pytest.mark.parametrize("cat_ordered", [True, False])
+    def test_astype_category(self, dtype_ordered, cat_ordered):
+        # GH 10696/18593
+        data = list("abcaacbab")
+        cat = Categorical(data, categories=list("bac"), ordered=cat_ordered)
+
+        # standard categories
+        dtype = CategoricalDtype(ordered=dtype_ordered)
+        result = cat.astype(dtype)
+        expected = Categorical(data, categories=cat.categories, ordered=dtype_ordered)
+        tm.assert_categorical_equal(result, expected)
+
+        # non-standard categories
+        dtype = CategoricalDtype(list("adc"), dtype_ordered)
+        result = cat.astype(dtype)
+        expected = Categorical(data, dtype=dtype)
+        tm.assert_categorical_equal(result, expected)
+
+        if dtype_ordered is False:
+            # dtype='category' can't specify ordered, so only test once
+            result = cat.astype("category")
+            expected = cat
+            tm.assert_categorical_equal(result, expected)
+
+    def test_astype_category_ordered_none_deprecated(self):
+        # GH 26336
+        cdt1 = CategoricalDtype(categories=list("cdab"), ordered=True)
+        cdt2 = CategoricalDtype(categories=list("cedafb"))
+        cat = Categorical(list("abcdaba"), dtype=cdt1)
+        with tm.assert_produces_warning(FutureWarning):
+            cat.astype(cdt2)
+
+    def test_iter_python_types(self):
+        # GH-19909
+        cat = Categorical([1, 2])
+        assert isinstance(list(cat)[0], int)
+        assert isinstance(cat.tolist()[0], int)
+
+    def test_iter_python_types_datetime(self):
+        cat = Categorical([Timestamp("2017-01-01"), Timestamp("2017-01-02")])
+        assert isinstance(list(cat)[0], Timestamp)
+        assert isinstance(cat.tolist()[0], Timestamp)

venv/lib/python3.6/site-packages/pandas/tests/arrays/categorical/test_indexing.py

@@ -0,0 +1,279 @@
+import numpy as np
+import pytest
+
+import pandas as pd
+from pandas import Categorical, CategoricalIndex, Index, PeriodIndex, Series
+import pandas.core.common as com
+from pandas.tests.arrays.categorical.common import TestCategorical
+import pandas.util.testing as tm
+
+
+class TestCategoricalIndexingWithFactor(TestCategorical):
+    def test_getitem(self):
+        assert self.factor[0] == "a"
+        assert self.factor[-1] == "c"
+
+        subf = self.factor[[0, 1, 2]]
+        tm.assert_numpy_array_equal(subf._codes, np.array([0, 1, 1], dtype=np.int8))
+
+        subf = self.factor[np.asarray(self.factor) == "c"]
+        tm.assert_numpy_array_equal(subf._codes, np.array([2, 2, 2], dtype=np.int8))
+
+    def test_setitem(self):
+
+        # int/positional
+        c = self.factor.copy()
+        c[0] = "b"
+        assert c[0] == "b"
+        c[-1] = "a"
+        assert c[-1] == "a"
+
+        # boolean
+        c = self.factor.copy()
+        indexer = np.zeros(len(c), dtype="bool")
+        indexer[0] = True
+        indexer[-1] = True
+        c[indexer] = "c"
+        expected = Categorical(["c", "b", "b", "a", "a", "c", "c", "c"], ordered=True)
+
+        tm.assert_categorical_equal(c, expected)
+
+    @pytest.mark.parametrize(
+        "other",
+        [pd.Categorical(["b", "a"]), pd.Categorical(["b", "a"], categories=["b", "a"])],
+    )
+    def test_setitem_same_but_unordered(self, other):
+        # GH-24142
+        target = pd.Categorical(["a", "b"], categories=["a", "b"])
+        mask = np.array([True, False])
+        target[mask] = other[mask]
+        expected = pd.Categorical(["b", "b"], categories=["a", "b"])
+        tm.assert_categorical_equal(target, expected)
+
+    @pytest.mark.parametrize(
+        "other",
+        [
+            pd.Categorical(["b", "a"], categories=["b", "a", "c"]),
+            pd.Categorical(["b", "a"], categories=["a", "b", "c"]),
+            pd.Categorical(["a", "a"], categories=["a"]),
+            pd.Categorical(["b", "b"], categories=["b"]),
+        ],
+    )
+    def test_setitem_different_unordered_raises(self, other):
+        # GH-24142
+        target = pd.Categorical(["a", "b"], categories=["a", "b"])
+        mask = np.array([True, False])
+        with pytest.raises(ValueError):
+            target[mask] = other[mask]
+
+    @pytest.mark.parametrize(
+        "other",
+        [
+            pd.Categorical(["b", "a"]),
+            pd.Categorical(["b", "a"], categories=["b", "a"], ordered=True),
+            pd.Categorical(["b", "a"], categories=["a", "b", "c"], ordered=True),
+        ],
+    )
+    def test_setitem_same_ordered_rasies(self, other):
+        # Gh-24142
+        target = pd.Categorical(["a", "b"], categories=["a", "b"], ordered=True)
+        mask = np.array([True, False])
+
+        with pytest.raises(ValueError):
+            target[mask] = other[mask]
+
+
+class TestCategoricalIndexing:
+    def test_getitem_listlike(self):
+
+        # GH 9469
+        # properly coerce the input indexers
+        np.random.seed(1)
+        c = Categorical(np.random.randint(0, 5, size=150000).astype(np.int8))
+        result = c.codes[np.array([100000]).astype(np.int64)]
+        expected = c[np.array([100000]).astype(np.int64)].codes
+        tm.assert_numpy_array_equal(result, expected)
+
+    def test_periodindex(self):
+        idx1 = PeriodIndex(
+            ["2014-01", "2014-01", "2014-02", "2014-02", "2014-03", "2014-03"], freq="M"
+        )
+
+        cat1 = Categorical(idx1)
+        str(cat1)
+        exp_arr = np.array([0, 0, 1, 1, 2, 2], dtype=np.int8)
+        exp_idx = PeriodIndex(["2014-01", "2014-02", "2014-03"], freq="M")
+        tm.assert_numpy_array_equal(cat1._codes, exp_arr)
+        tm.assert_index_equal(cat1.categories, exp_idx)
+
+        idx2 = PeriodIndex(
+            ["2014-03", "2014-03", "2014-02", "2014-01", "2014-03", "2014-01"], freq="M"
+        )
+        cat2 = Categorical(idx2, ordered=True)
+        str(cat2)
+        exp_arr = np.array([2, 2, 1, 0, 2, 0], dtype=np.int8)
+        exp_idx2 = PeriodIndex(["2014-01", "2014-02", "2014-03"], freq="M")
+        tm.assert_numpy_array_equal(cat2._codes, exp_arr)
+        tm.assert_index_equal(cat2.categories, exp_idx2)
+
+        idx3 = PeriodIndex(
+            [
+                "2013-12",
+                "2013-11",
+                "2013-10",
+                "2013-09",
+                "2013-08",
+                "2013-07",
+                "2013-05",
+            ],
+            freq="M",
+        )
+        cat3 = Categorical(idx3, ordered=True)
+        exp_arr = np.array([6, 5, 4, 3, 2, 1, 0], dtype=np.int8)
+        exp_idx = PeriodIndex(
+            [
+                "2013-05",
+                "2013-07",
+                "2013-08",
+                "2013-09",
+                "2013-10",
+                "2013-11",
+                "2013-12",
+            ],
+            freq="M",
+        )
+        tm.assert_numpy_array_equal(cat3._codes, exp_arr)
+        tm.assert_index_equal(cat3.categories, exp_idx)
+
+    def test_categories_assigments(self):
+        s = Categorical(["a", "b", "c", "a"])
+        exp = np.array([1, 2, 3, 1], dtype=np.int64)
+        s.categories = [1, 2, 3]
+        tm.assert_numpy_array_equal(s.__array__(), exp)
+        tm.assert_index_equal(s.categories, Index([1, 2, 3]))
+
+        # lengthen
+        with pytest.raises(ValueError):
+            s.categories = [1, 2, 3, 4]
+
+        # shorten
+        with pytest.raises(ValueError):
+            s.categories = [1, 2]
+
+    # Combinations of sorted/unique:
+    @pytest.mark.parametrize(
+        "idx_values", [[1, 2, 3, 4], [1, 3, 2, 4], [1, 3, 3, 4], [1, 2, 2, 4]]
+    )
+    # Combinations of missing/unique
+    @pytest.mark.parametrize("key_values", [[1, 2], [1, 5], [1, 1], [5, 5]])
+    @pytest.mark.parametrize("key_class", [Categorical, CategoricalIndex])
+    def test_get_indexer_non_unique(self, idx_values, key_values, key_class):
+        # GH 21448
+        key = key_class(key_values, categories=range(1, 5))
+        # Test for flat index and CategoricalIndex with same/different cats:
+        for dtype in None, "category", key.dtype:
+            idx = Index(idx_values, dtype=dtype)
+            expected, exp_miss = idx.get_indexer_non_unique(key_values)
+            result, res_miss = idx.get_indexer_non_unique(key)
+
+            tm.assert_numpy_array_equal(expected, result)
+            tm.assert_numpy_array_equal(exp_miss, res_miss)
+
+    def test_where_unobserved_nan(self):
+        ser = pd.Series(pd.Categorical(["a", "b"]))
+        result = ser.where([True, False])
+        expected = pd.Series(pd.Categorical(["a", None], categories=["a", "b"]))
+        tm.assert_series_equal(result, expected)
+
+        # all NA
+        ser = pd.Series(pd.Categorical(["a", "b"]))
+        result = ser.where([False, False])
+        expected = pd.Series(pd.Categorical([None, None], categories=["a", "b"]))
+        tm.assert_series_equal(result, expected)
+
+    def test_where_unobserved_categories(self):
+        ser = pd.Series(Categorical(["a", "b", "c"], categories=["d", "c", "b", "a"]))
+        result = ser.where([True, True, False], other="b")
+        expected = pd.Series(
+            Categorical(["a", "b", "b"], categories=ser.cat.categories)
+        )
+        tm.assert_series_equal(result, expected)
+
+    def test_where_other_categorical(self):
+        ser = pd.Series(Categorical(["a", "b", "c"], categories=["d", "c", "b", "a"]))
+        other = Categorical(["b", "c", "a"], categories=["a", "c", "b", "d"])
+        result = ser.where([True, False, True], other)
+        expected = pd.Series(Categorical(["a", "c", "c"], dtype=ser.dtype))
+        tm.assert_series_equal(result, expected)
+
+    def test_where_warns(self):
+        ser = pd.Series(Categorical(["a", "b", "c"]))
+        with tm.assert_produces_warning(FutureWarning):
+            result = ser.where([True, False, True], "d")
+
+        expected = pd.Series(np.array(["a", "d", "c"], dtype="object"))
+        tm.assert_series_equal(result, expected)
+
+    def test_where_ordered_differs_rasies(self):
+        ser = pd.Series(
+            Categorical(["a", "b", "c"], categories=["d", "c", "b", "a"], ordered=True)
+        )
+        other = Categorical(
+            ["b", "c", "a"], categories=["a", "c", "b", "d"], ordered=True
+        )
+        with tm.assert_produces_warning(FutureWarning):
+            result = ser.where([True, False, True], other)
+
+        expected = pd.Series(np.array(["a", "c", "c"], dtype=object))
+        tm.assert_series_equal(result, expected)
+
+
+@pytest.mark.parametrize("index", [True, False])
+def test_mask_with_boolean(index):
+    s = Series(range(3))
+    idx = Categorical([True, False, True])
+    if index:
+        idx = CategoricalIndex(idx)
+
+    assert com.is_bool_indexer(idx)
+    result = s[idx]
+    expected = s[idx.astype("object")]
+    tm.assert_series_equal(result, expected)
+
+
+@pytest.mark.parametrize("index", [True, False])
+def test_mask_with_boolean_raises(index):
+    s = Series(range(3))
+    idx = Categorical([True, False, None])
+    if index:
+        idx = CategoricalIndex(idx)
+
+    with pytest.raises(ValueError, match="NA / NaN"):
+        s[idx]
+
+
+@pytest.fixture
+def non_coercible_categorical(monkeypatch):
+    """
+    Monkeypatch Categorical.__array__ to ensure no implicit conversion.
+
+    Raises
+    ------
+    ValueError
+        When Categorical.__array__ is called.
+    """
+    # TODO(Categorical): identify other places where this may be
+    # useful and move to a conftest.py
+    def array(self, dtype=None):
+        raise ValueError("I cannot be converted.")
+
+    with monkeypatch.context() as m:
+        m.setattr(Categorical, "__array__", array)
+        yield
+
+
+def test_series_at(non_coercible_categorical):
+    arr = Categorical(["a", "b", "c"])
+    ser = Series(arr)
+    result = ser.at[0]
+    assert result == "a"

venv/lib/python3.6/site-packages/pandas/tests/arrays/categorical/test_missing.py

@@ -0,0 +1,82 @@
+import collections
+
+import numpy as np
+import pytest
+
+from pandas.core.dtypes.dtypes import CategoricalDtype
+
+from pandas import Categorical, Index, isna
+import pandas.util.testing as tm
+
+
+class TestCategoricalMissing:
+    def test_na_flags_int_categories(self):
+        # #1457
+
+        categories = list(range(10))
+        labels = np.random.randint(0, 10, 20)
+        labels[::5] = -1
+
+        cat = Categorical(labels, categories, fastpath=True)
+        repr(cat)
+
+        tm.assert_numpy_array_equal(isna(cat), labels == -1)
+
+    def test_nan_handling(self):
+
+        # Nans are represented as -1 in codes
+        c = Categorical(["a", "b", np.nan, "a"])
+        tm.assert_index_equal(c.categories, Index(["a", "b"]))
+        tm.assert_numpy_array_equal(c._codes, np.array([0, 1, -1, 0], dtype=np.int8))
+        c[1] = np.nan
+        tm.assert_index_equal(c.categories, Index(["a", "b"]))
+        tm.assert_numpy_array_equal(c._codes, np.array([0, -1, -1, 0], dtype=np.int8))
+
+        # Adding nan to categories should make assigned nan point to the
+        # category!
+        c = Categorical(["a", "b", np.nan, "a"])
+        tm.assert_index_equal(c.categories, Index(["a", "b"]))
+        tm.assert_numpy_array_equal(c._codes, np.array([0, 1, -1, 0], dtype=np.int8))
+
+    def test_set_dtype_nans(self):
+        c = Categorical(["a", "b", np.nan])
+        result = c._set_dtype(CategoricalDtype(["a", "c"]))
+        tm.assert_numpy_array_equal(result.codes, np.array([0, -1, -1], dtype="int8"))
+
+    def test_set_item_nan(self):
+        cat = Categorical([1, 2, 3])
+        cat[1] = np.nan
+
+        exp = Categorical([1, np.nan, 3], categories=[1, 2, 3])
+        tm.assert_categorical_equal(cat, exp)
+
+    @pytest.mark.parametrize(
+        "fillna_kwargs, msg",
+        [
+            (
+                dict(value=1, method="ffill"),
+                "Cannot specify both 'value' and 'method'.",
+            ),
+            (dict(), "Must specify a fill 'value' or 'method'."),
+            (dict(method="bad"), "Invalid fill method. Expecting .* bad"),
+        ],
+    )
+    def test_fillna_raises(self, fillna_kwargs, msg):
+        # https://github.com/pandas-dev/pandas/issues/19682
+        cat = Categorical([1, 2, 3])
+
+        with pytest.raises(ValueError, match=msg):
+            cat.fillna(**fillna_kwargs)
+
+    @pytest.mark.parametrize("named", [True, False])
+    def test_fillna_iterable_category(self, named):
+        # https://github.com/pandas-dev/pandas/issues/21097
+        if named:
+            Point = collections.namedtuple("Point", "x y")
+        else:
+            Point = lambda *args: args  # tuple
+        cat = Categorical([Point(0, 0), Point(0, 1), None])
+        result = cat.fillna(Point(0, 0))
+        expected = Categorical([Point(0, 0), Point(0, 1), Point(0, 0)])
+
+        tm.assert_categorical_equal(result, expected)

venv/lib/python3.6/site-packages/pandas/tests/arrays/categorical/test_operators.py

@@ -0,0 +1,431 @@
+import operator
+import warnings
+
+import numpy as np
+import pytest
+
+import pandas as pd
+from pandas import Categorical, DataFrame, Series, date_range
+from pandas.tests.arrays.categorical.common import TestCategorical
+import pandas.util.testing as tm
+
+
+class TestCategoricalOpsWithFactor(TestCategorical):
+    def test_categories_none_comparisons(self):
+        factor = Categorical(["a", "b", "b", "a", "a", "c", "c", "c"], ordered=True)
+        tm.assert_categorical_equal(factor, self.factor)
+
+    def test_comparisons(self):
+        result = self.factor[self.factor == "a"]
+        expected = self.factor[np.asarray(self.factor) == "a"]
+        tm.assert_categorical_equal(result, expected)
+
+        result = self.factor[self.factor != "a"]
+        expected = self.factor[np.asarray(self.factor) != "a"]
+        tm.assert_categorical_equal(result, expected)
+
+        result = self.factor[self.factor < "c"]
+        expected = self.factor[np.asarray(self.factor) < "c"]
+        tm.assert_categorical_equal(result, expected)
+
+        result = self.factor[self.factor > "a"]
+        expected = self.factor[np.asarray(self.factor) > "a"]
+        tm.assert_categorical_equal(result, expected)
+
+        result = self.factor[self.factor >= "b"]
+        expected = self.factor[np.asarray(self.factor) >= "b"]
+        tm.assert_categorical_equal(result, expected)
+
+        result = self.factor[self.factor <= "b"]
+        expected = self.factor[np.asarray(self.factor) <= "b"]
+        tm.assert_categorical_equal(result, expected)
+
+        n = len(self.factor)
+
+        other = self.factor[np.random.permutation(n)]
+        result = self.factor == other
+        expected = np.asarray(self.factor) == np.asarray(other)
+        tm.assert_numpy_array_equal(result, expected)
+
+        result = self.factor == "d"
+        expected = np.repeat(False, len(self.factor))
+        tm.assert_numpy_array_equal(result, expected)
+
+        # comparisons with categoricals
+        cat_rev = Categorical(["a", "b", "c"], categories=["c", "b", "a"], ordered=True)
+        cat_rev_base = Categorical(
+            ["b", "b", "b"], categories=["c", "b", "a"], ordered=True
+        )
+        cat = Categorical(["a", "b", "c"], ordered=True)
+        cat_base = Categorical(["b", "b", "b"], categories=cat.categories, ordered=True)
+
+        # comparisons need to take categories ordering into account
+        res_rev = cat_rev > cat_rev_base
+        exp_rev = np.array([True, False, False])
+        tm.assert_numpy_array_equal(res_rev, exp_rev)
+
+        res_rev = cat_rev < cat_rev_base
+        exp_rev = np.array([False, False, True])
+        tm.assert_numpy_array_equal(res_rev, exp_rev)
+
+        res = cat > cat_base
+        exp = np.array([False, False, True])
+        tm.assert_numpy_array_equal(res, exp)
+
+        # Only categories with same categories can be compared
+        with pytest.raises(TypeError):
+            cat > cat_rev
+
+        cat_rev_base2 = Categorical(["b", "b", "b"], categories=["c", "b", "a", "d"])
+
+        with pytest.raises(TypeError):
+            cat_rev > cat_rev_base2
+
+        # Only categories with same ordering information can be compared
+        cat_unorderd = cat.set_ordered(False)
+        assert not (cat > cat).any()
+
+        with pytest.raises(TypeError):
+            cat > cat_unorderd
+
+        # comparison (in both directions) with Series will raise
+        s = Series(["b", "b", "b"])
+        msg = (
+            "Cannot compare a Categorical for op __gt__ with type"
+            r" <class 'numpy\.ndarray'>"
+        )
+        with pytest.raises(TypeError, match=msg):
+            cat > s
+        with pytest.raises(TypeError, match=msg):
+            cat_rev > s
+        with pytest.raises(TypeError, match=msg):
+            s < cat
+        with pytest.raises(TypeError, match=msg):
+            s < cat_rev
+
+        # comparison with numpy.array will raise in both direction, but only on
+        # newer numpy versions
+        a = np.array(["b", "b", "b"])
+        with pytest.raises(TypeError, match=msg):
+            cat > a
+        with pytest.raises(TypeError, match=msg):
+            cat_rev > a
+
+        # Make sure that unequal comparison take the categories order in
+        # account
+        cat_rev = Categorical(list("abc"), categories=list("cba"), ordered=True)
+        exp = np.array([True, False, False])
+        res = cat_rev > "b"
+        tm.assert_numpy_array_equal(res, exp)
+
+        # check that zero-dim array gets unboxed
+        res = cat_rev > np.array("b")
+        tm.assert_numpy_array_equal(res, exp)
+
+
+class TestCategoricalOps:
+    def test_compare_frame(self):
+        # GH#24282 check that Categorical.__cmp__(DataFrame) defers to frame
+        data = ["a", "b", 2, "a"]
+        cat = Categorical(data)
+
+        df = DataFrame(cat)
+
+        for op in [
+            operator.eq,
+            operator.ne,
+            operator.ge,
+            operator.gt,
+            operator.le,
+            operator.lt,
+        ]:
+            with pytest.raises(ValueError):
+                # alignment raises unless we transpose
+                op(cat, df)
+
+        result = cat == df.T
+        expected = DataFrame([[True, True, True, True]])
+        tm.assert_frame_equal(result, expected)
+
+        result = cat[::-1] != df.T
+        expected = DataFrame([[False, True, True, False]])
+        tm.assert_frame_equal(result, expected)
+
+    def test_datetime_categorical_comparison(self):
+        dt_cat = Categorical(date_range("2014-01-01", periods=3), ordered=True)
+        tm.assert_numpy_array_equal(dt_cat > dt_cat[0], np.array([False, True, True]))
+        tm.assert_numpy_array_equal(dt_cat[0] < dt_cat, np.array([False, True, True]))
+
+    def test_reflected_comparison_with_scalars(self):
+        # GH8658
+        cat = Categorical([1, 2, 3], ordered=True)
+        tm.assert_numpy_array_equal(cat > cat[0], np.array([False, True, True]))
+        tm.assert_numpy_array_equal(cat[0] < cat, np.array([False, True, True]))
+
+    def test_comparison_with_unknown_scalars(self):
+        # https://github.com/pandas-dev/pandas/issues/9836#issuecomment-92123057
+        # and following comparisons with scalars not in categories should raise
+        # for unequal comps, but not for equal/not equal
+        cat = Categorical([1, 2, 3], ordered=True)
+
+        msg = (
+            "Cannot compare a Categorical for op __{}__ with a scalar,"
+            " which is not a category"
+        )
+        with pytest.raises(TypeError, match=msg.format("lt")):
+            cat < 4
+        with pytest.raises(TypeError, match=msg.format("gt")):
+            cat > 4
+        with pytest.raises(TypeError, match=msg.format("gt")):
+            4 < cat
+        with pytest.raises(TypeError, match=msg.format("lt")):
+            4 > cat
+
+        tm.assert_numpy_array_equal(cat == 4, np.array([False, False, False]))
+        tm.assert_numpy_array_equal(cat != 4, np.array([True, True, True]))
+
+    def test_comparison_of_ordered_categorical_with_nan_to_scalar(
+        self, compare_operators_no_eq_ne
+    ):
+        # https://github.com/pandas-dev/pandas/issues/26504
+        # BUG: fix ordered categorical comparison with missing values (#26504 )
+        # and following comparisons with scalars in categories with missing
+        # values should be evaluated as False
+
+        cat = Categorical([1, 2, 3, None], categories=[1, 2, 3], ordered=True)
+        scalar = 2
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", RuntimeWarning)
+            expected = getattr(np.array(cat), compare_operators_no_eq_ne)(scalar)
+        actual = getattr(cat, compare_operators_no_eq_ne)(scalar)
+        tm.assert_numpy_array_equal(actual, expected)
+
+    def test_comparison_of_ordered_categorical_with_nan_to_listlike(
+        self, compare_operators_no_eq_ne
+    ):
+        # https://github.com/pandas-dev/pandas/issues/26504
+        # and following comparisons of missing values in ordered Categorical
+        # with listlike should be evaluated as False
+
+        cat = Categorical([1, 2, 3, None], categories=[1, 2, 3], ordered=True)
+        other = Categorical([2, 2, 2, 2], categories=[1, 2, 3], ordered=True)
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", RuntimeWarning)
+            expected = getattr(np.array(cat), compare_operators_no_eq_ne)(2)
+        actual = getattr(cat, compare_operators_no_eq_ne)(other)
+        tm.assert_numpy_array_equal(actual, expected)
+
+    @pytest.mark.parametrize(
+        "data,reverse,base",
+        [(list("abc"), list("cba"), list("bbb")), ([1, 2, 3], [3, 2, 1], [2, 2, 2])],
+    )
+    def test_comparisons(self, data, reverse, base):
+        cat_rev = Series(Categorical(data, categories=reverse, ordered=True))
+        cat_rev_base = Series(Categorical(base, categories=reverse, ordered=True))
+        cat = Series(Categorical(data, ordered=True))
+        cat_base = Series(
+            Categorical(base, categories=cat.cat.categories, ordered=True)
+        )
+        s = Series(base)
+        a = np.array(base)
+
+        # comparisons need to take categories ordering into account
+        res_rev = cat_rev > cat_rev_base
+        exp_rev = Series([True, False, False])
+        tm.assert_series_equal(res_rev, exp_rev)
+
+        res_rev = cat_rev < cat_rev_base
+        exp_rev = Series([False, False, True])
+        tm.assert_series_equal(res_rev, exp_rev)
+
+        res = cat > cat_base
+        exp = Series([False, False, True])
+        tm.assert_series_equal(res, exp)
+
+        scalar = base[1]
+        res = cat > scalar
+        exp = Series([False, False, True])
+        exp2 = cat.values > scalar
+        tm.assert_series_equal(res, exp)
+        tm.assert_numpy_array_equal(res.values, exp2)
+        res_rev = cat_rev > scalar
+        exp_rev = Series([True, False, False])
+        exp_rev2 = cat_rev.values > scalar
+        tm.assert_series_equal(res_rev, exp_rev)
+        tm.assert_numpy_array_equal(res_rev.values, exp_rev2)
+
+        # Only categories with same categories can be compared
+        with pytest.raises(TypeError):
+            cat > cat_rev
+
+        # categorical cannot be compared to Series or numpy array, and also
+        # not the other way around
+        msg = (
+            "Cannot compare a Categorical for op __gt__ with type"
+            r" <class 'numpy\.ndarray'>"
+        )
+        with pytest.raises(TypeError, match=msg):
+            cat > s
+        with pytest.raises(TypeError, match=msg):
+            cat_rev > s
+        with pytest.raises(TypeError, match=msg):
+            cat > a
+        with pytest.raises(TypeError, match=msg):
+            cat_rev > a
+
+        with pytest.raises(TypeError, match=msg):
+            s < cat
+        with pytest.raises(TypeError, match=msg):
+            s < cat_rev
+
+        with pytest.raises(TypeError, match=msg):
+            a < cat
+        with pytest.raises(TypeError, match=msg):
+            a < cat_rev
+
+    @pytest.mark.parametrize(
+        "ctor",
+        [
+            lambda *args, **kwargs: Categorical(*args, **kwargs),
+            lambda *args, **kwargs: Series(Categorical(*args, **kwargs)),
+        ],
+    )
+    def test_unordered_different_order_equal(self, ctor):
+        # https://github.com/pandas-dev/pandas/issues/16014
+        c1 = ctor(["a", "b"], categories=["a", "b"], ordered=False)
+        c2 = ctor(["a", "b"], categories=["b", "a"], ordered=False)
+        assert (c1 == c2).all()
+
+        c1 = ctor(["a", "b"], categories=["a", "b"], ordered=False)
+        c2 = ctor(["b", "a"], categories=["b", "a"], ordered=False)
+        assert (c1 != c2).all()
+
+        c1 = ctor(["a", "a"], categories=["a", "b"], ordered=False)
+        c2 = ctor(["b", "b"], categories=["b", "a"], ordered=False)
+        assert (c1 != c2).all()
+
+        c1 = ctor(["a", "a"], categories=["a", "b"], ordered=False)
+        c2 = ctor(["a", "b"], categories=["b", "a"], ordered=False)
+        result = c1 == c2
+        tm.assert_numpy_array_equal(np.array(result), np.array([True, False]))
+
+    def test_unordered_different_categories_raises(self):
+        c1 = Categorical(["a", "b"], categories=["a", "b"], ordered=False)
+        c2 = Categorical(["a", "c"], categories=["c", "a"], ordered=False)
+
+        with pytest.raises(TypeError, match=("Categoricals can only be compared")):
+            c1 == c2
+
+    def test_compare_different_lengths(self):
+        c1 = Categorical([], categories=["a", "b"])
+        c2 = Categorical([], categories=["a"])
+
+        msg = "Categories are different lengths"
+        with pytest.raises(TypeError, match=msg):
+            c1 == c2
+
+    def test_compare_unordered_different_order(self):
+        # https://github.com/pandas-dev/pandas/issues/16603#issuecomment-
+        # 349290078
+        a = pd.Categorical(["a"], categories=["a", "b"])
+        b = pd.Categorical(["b"], categories=["b", "a"])
+        assert not a.equals(b)
+
+    def test_numeric_like_ops(self):
+
+        df = DataFrame({"value": np.random.randint(0, 10000, 100)})
+        labels = ["{0} - {1}".format(i, i + 499) for i in range(0, 10000, 500)]
+        cat_labels = Categorical(labels, labels)
+
+        df = df.sort_values(by=["value"], ascending=True)
+        df["value_group"] = pd.cut(
+            df.value, range(0, 10500, 500), right=False, labels=cat_labels
+        )
+
+        # numeric ops should not succeed
+        for op, str_rep in [
+            ("__add__", r"\+"),
+            ("__sub__", "-"),
+            ("__mul__", r"\*"),
+            ("__truediv__", "/"),
+        ]:
+            msg = r"Series cannot perform the operation {}".format(str_rep)
+            with pytest.raises(TypeError, match=msg):
+                getattr(df, op)(df)
+
+        # reduction ops should not succeed (unless specifically defined, e.g.
+        # min/max)
+        s = df["value_group"]
+        for op in ["kurt", "skew", "var", "std", "mean", "sum", "median"]:
+            msg = "Categorical cannot perform the operation {}".format(op)
+            with pytest.raises(TypeError, match=msg):
+                getattr(s, op)(numeric_only=False)
+
+        # mad technically works because it takes always the numeric data
+
+        # numpy ops
+        s = Series(Categorical([1, 2, 3, 4]))
+        with pytest.raises(TypeError):
+            np.sum(s)
+
+        # numeric ops on a Series
+        for op, str_rep in [
+            ("__add__", r"\+"),
+            ("__sub__", "-"),
+            ("__mul__", r"\*"),
+            ("__truediv__", "/"),
+        ]:
+            msg = r"Series cannot perform the operation {}".format(str_rep)
+            with pytest.raises(TypeError, match=msg):
+                getattr(s, op)(2)
+
+        # invalid ufunc
+        with pytest.raises(TypeError):
+            np.log(s)
+
+    def test_contains(self):
+        # GH21508
+        c = pd.Categorical(list("aabbca"), categories=list("cab"))
+
+        assert "b" in c
+        assert "z" not in c
+        assert np.nan not in c
+        with pytest.raises(TypeError):
+            assert [1] in c
+
+        # assert codes NOT in index
+        assert 0 not in c
+        assert 1 not in c
+
+        c = pd.Categorical(list("aabbca") + [np.nan], categories=list("cab"))
+        assert np.nan in c
+
+    @pytest.mark.parametrize(
+        "item, expected",
+        [
+            (pd.Interval(0, 1), True),
+            (1.5, True),
+            (pd.Interval(0.5, 1.5), False),
+            ("a", False),
+            (pd.Timestamp(1), False),
+            (pd.Timedelta(1), False),
+        ],
+        ids=str,
+    )
+    def test_contains_interval(self, item, expected):
+        # GH 23705
+        cat = Categorical(pd.IntervalIndex.from_breaks(range(3)))
+        result = item in cat
+        assert result is expected
+
+    def test_contains_list(self):
+        # GH#21729
+        cat = Categorical([1, 2, 3])
+
+        assert "a" not in cat
+
+        with pytest.raises(TypeError, match="unhashable type"):
+            ["a"] in cat
+
+        with pytest.raises(TypeError, match="unhashable type"):
+            ["a", "b"] in cat

venv/lib/python3.6/site-packages/pandas/tests/arrays/categorical/test_repr.py

@@ -0,0 +1,527 @@
+import numpy as np
+
+from pandas import (
+    Categorical,
+    CategoricalIndex,
+    Series,
+    date_range,
+    option_context,
+    period_range,
+    timedelta_range,
+)
+from pandas.tests.arrays.categorical.common import TestCategorical
+
+
+class TestCategoricalReprWithFactor(TestCategorical):
+    def test_print(self):
+        expected = ["[a, b, b, a, a, c, c, c]", "Categories (3, object): [a < b < c]"]
+        expected = "\n".join(expected)
+        actual = repr(self.factor)
+        assert actual == expected
+
+
+class TestCategoricalRepr:
+    def test_big_print(self):
+        factor = Categorical([0, 1, 2, 0, 1, 2] * 100, ["a", "b", "c"], fastpath=True)
+        expected = [
+            "[a, b, c, a, b, ..., b, c, a, b, c]",
+            "Length: 600",
+            "Categories (3, object): [a, b, c]",
+        ]
+        expected = "\n".join(expected)
+
+        actual = repr(factor)
+
+        assert actual == expected
+
+    def test_empty_print(self):
+        factor = Categorical([], ["a", "b", "c"])
+        expected = "[], Categories (3, object): [a, b, c]"
+        actual = repr(factor)
+        assert actual == expected
+
+        assert expected == actual
+        factor = Categorical([], ["a", "b", "c"], ordered=True)
+        expected = "[], Categories (3, object): [a < b < c]"
+        actual = repr(factor)
+        assert expected == actual
+
+        factor = Categorical([], [])
+        expected = "[], Categories (0, object): []"
+        assert expected == repr(factor)
+
+    def test_print_none_width(self):
+        # GH10087
+        a = Series(Categorical([1, 2, 3, 4]))
+        exp = (
+            "0    1\n1    2\n2    3\n3    4\n"
+            "dtype: category\nCategories (4, int64): [1, 2, 3, 4]"
+        )
+
+        with option_context("display.width", None):
+            assert exp == repr(a)
+
+    def test_unicode_print(self):
+        c = Categorical(["aaaaa", "bb", "cccc"] * 20)
+        expected = """\
+[aaaaa, bb, cccc, aaaaa, bb, ..., bb, cccc, aaaaa, bb, cccc]
+Length: 60
+Categories (3, object): [aaaaa, bb, cccc]"""
+
+        assert repr(c) == expected
+
+        c = Categorical(["ああああ", "いいいいい", "ううううううう"] * 20)
+        expected = """\
+[ああああ, いいいいい, ううううううう, ああああ, いいいいい, ..., いいいいい, ううううううう, ああああ, いいいいい, ううううううう]
+Length: 60
+Categories (3, object): [ああああ, いいいいい, ううううううう]"""  # noqa
+
+        assert repr(c) == expected
+
+        # unicode option should not affect to Categorical, as it doesn't care
+        # the repr width
+        with option_context("display.unicode.east_asian_width", True):
+
+            c = Categorical(["ああああ", "いいいいい", "ううううううう"] * 20)
+            expected = """[ああああ, いいいいい, ううううううう, ああああ, いいいいい, ..., いいいいい, ううううううう, ああああ, いいいいい, ううううううう]
+Length: 60
+Categories (3, object): [ああああ, いいいいい, ううううううう]"""  # noqa
+
+            assert repr(c) == expected
+
+    def test_categorical_repr(self):
+        c = Categorical([1, 2, 3])
+        exp = """[1, 2, 3]
+Categories (3, int64): [1, 2, 3]"""
+
+        assert repr(c) == exp
+
+        c = Categorical([1, 2, 3, 1, 2, 3], categories=[1, 2, 3])
+        exp = """[1, 2, 3, 1, 2, 3]
+Categories (3, int64): [1, 2, 3]"""
+
+        assert repr(c) == exp
+
+        c = Categorical([1, 2, 3, 4, 5] * 10)
+        exp = """[1, 2, 3, 4, 5, ..., 1, 2, 3, 4, 5]
+Length: 50
+Categories (5, int64): [1, 2, 3, 4, 5]"""
+
+        assert repr(c) == exp
+
+        c = Categorical(np.arange(20))
+        exp = """[0, 1, 2, 3, 4, ..., 15, 16, 17, 18, 19]
+Length: 20
+Categories (20, int64): [0, 1, 2, 3, ..., 16, 17, 18, 19]"""
+
+        assert repr(c) == exp
+
+    def test_categorical_repr_ordered(self):
+        c = Categorical([1, 2, 3], ordered=True)
+        exp = """[1, 2, 3]
+Categories (3, int64): [1 < 2 < 3]"""
+
+        assert repr(c) == exp
+
+        c = Categorical([1, 2, 3, 1, 2, 3], categories=[1, 2, 3], ordered=True)
+        exp = """[1, 2, 3, 1, 2, 3]
+Categories (3, int64): [1 < 2 < 3]"""
+
+        assert repr(c) == exp
+
+        c = Categorical([1, 2, 3, 4, 5] * 10, ordered=True)
+        exp = """[1, 2, 3, 4, 5, ..., 1, 2, 3, 4, 5]
+Length: 50
+Categories (5, int64): [1 < 2 < 3 < 4 < 5]"""
+
+        assert repr(c) == exp
+
+        c = Categorical(np.arange(20), ordered=True)
+        exp = """[0, 1, 2, 3, 4, ..., 15, 16, 17, 18, 19]
+Length: 20
+Categories (20, int64): [0 < 1 < 2 < 3 ... 16 < 17 < 18 < 19]"""
+
+        assert repr(c) == exp
+
+    def test_categorical_repr_datetime(self):
+        idx = date_range("2011-01-01 09:00", freq="H", periods=5)
+        c = Categorical(idx)
+
+        # TODO(wesm): exceeding 80 characters in the console is not good
+        # behavior
+        exp = (
+            "[2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00, "
+            "2011-01-01 12:00:00, 2011-01-01 13:00:00]\n"
+            "Categories (5, datetime64[ns]): [2011-01-01 09:00:00, "
+            "2011-01-01 10:00:00, 2011-01-01 11:00:00,\n"
+            "                                 2011-01-01 12:00:00, "
+            "2011-01-01 13:00:00]"
+            ""
+        )
+        assert repr(c) == exp
+
+        c = Categorical(idx.append(idx), categories=idx)
+        exp = (
+            "[2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00, "
+            "2011-01-01 12:00:00, 2011-01-01 13:00:00, 2011-01-01 09:00:00, "
+            "2011-01-01 10:00:00, 2011-01-01 11:00:00, 2011-01-01 12:00:00, "
+            "2011-01-01 13:00:00]\n"
+            "Categories (5, datetime64[ns]): [2011-01-01 09:00:00, "
+            "2011-01-01 10:00:00, 2011-01-01 11:00:00,\n"
+            "                                 2011-01-01 12:00:00, "
+            "2011-01-01 13:00:00]"
+        )
+
+        assert repr(c) == exp
+
+        idx = date_range("2011-01-01 09:00", freq="H", periods=5, tz="US/Eastern")
+        c = Categorical(idx)
+        exp = (
+            "[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, "
+            "2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, "
+            "2011-01-01 13:00:00-05:00]\n"
+            "Categories (5, datetime64[ns, US/Eastern]): "
+            "[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00,\n"
+            "                                             "
+            "2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00,\n"
+            "                                             "
+            "2011-01-01 13:00:00-05:00]"
+        )
+
+        assert repr(c) == exp
+
+        c = Categorical(idx.append(idx), categories=idx)
+        exp = (
+            "[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, "
+            "2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, "
+            "2011-01-01 13:00:00-05:00, 2011-01-01 09:00:00-05:00, "
+            "2011-01-01 10:00:00-05:00, 2011-01-01 11:00:00-05:00, "
+            "2011-01-01 12:00:00-05:00, 2011-01-01 13:00:00-05:00]\n"
+            "Categories (5, datetime64[ns, US/Eastern]): "
+            "[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00,\n"
+            "                                             "
+            "2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00,\n"
+            "                                             "
+            "2011-01-01 13:00:00-05:00]"
+        )
+
+        assert repr(c) == exp
+
+    def test_categorical_repr_datetime_ordered(self):
+        idx = date_range("2011-01-01 09:00", freq="H", periods=5)
+        c = Categorical(idx, ordered=True)
+        exp = """[2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00, 2011-01-01 12:00:00, 2011-01-01 13:00:00]
+Categories (5, datetime64[ns]): [2011-01-01 09:00:00 < 2011-01-01 10:00:00 < 2011-01-01 11:00:00 <
+                                 2011-01-01 12:00:00 < 2011-01-01 13:00:00]"""  # noqa
+
+        assert repr(c) == exp
+
+        c = Categorical(idx.append(idx), categories=idx, ordered=True)
+        exp = """[2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00, 2011-01-01 12:00:00, 2011-01-01 13:00:00, 2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00, 2011-01-01 12:00:00, 2011-01-01 13:00:00]
+Categories (5, datetime64[ns]): [2011-01-01 09:00:00 < 2011-01-01 10:00:00 < 2011-01-01 11:00:00 <
+                                 2011-01-01 12:00:00 < 2011-01-01 13:00:00]"""  # noqa
+
+        assert repr(c) == exp
+
+        idx = date_range("2011-01-01 09:00", freq="H", periods=5, tz="US/Eastern")
+        c = Categorical(idx, ordered=True)
+        exp = """[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, 2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, 2011-01-01 13:00:00-05:00]
+Categories (5, datetime64[ns, US/Eastern]): [2011-01-01 09:00:00-05:00 < 2011-01-01 10:00:00-05:00 <
+                                             2011-01-01 11:00:00-05:00 < 2011-01-01 12:00:00-05:00 <
+                                             2011-01-01 13:00:00-05:00]"""  # noqa
+
+        assert repr(c) == exp
+
+        c = Categorical(idx.append(idx), categories=idx, ordered=True)
+        exp = """[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, 2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, 2011-01-01 13:00:00-05:00, 2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, 2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, 2011-01-01 13:00:00-05:00]
+Categories (5, datetime64[ns, US/Eastern]): [2011-01-01 09:00:00-05:00 < 2011-01-01 10:00:00-05:00 <
+                                             2011-01-01 11:00:00-05:00 < 2011-01-01 12:00:00-05:00 <
+                                             2011-01-01 13:00:00-05:00]"""  # noqa
+
+        assert repr(c) == exp
+
+    def test_categorical_repr_int_with_nan(self):
+        c = Categorical([1, 2, np.nan])
+        c_exp = """[1, 2, NaN]\nCategories (2, int64): [1, 2]"""
+        assert repr(c) == c_exp
+
+        s = Series([1, 2, np.nan], dtype="object").astype("category")
+        s_exp = """0      1\n1      2\n2    NaN
+dtype: category
+Categories (2, int64): [1, 2]"""
+        assert repr(s) == s_exp
+
+    def test_categorical_repr_period(self):
+        idx = period_range("2011-01-01 09:00", freq="H", periods=5)
+        c = Categorical(idx)
+        exp = """[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00]
+Categories (5, period[H]): [2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00,
+                            2011-01-01 13:00]"""  # noqa
+
+        assert repr(c) == exp
+
+        c = Categorical(idx.append(idx), categories=idx)
+        exp = """[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00, 2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00]
+Categories (5, period[H]): [2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00,
+                            2011-01-01 13:00]"""  # noqa
+
+        assert repr(c) == exp
+
+        idx = period_range("2011-01", freq="M", periods=5)
+        c = Categorical(idx)
+        exp = """[2011-01, 2011-02, 2011-03, 2011-04, 2011-05]
+Categories (5, period[M]): [2011-01, 2011-02, 2011-03, 2011-04, 2011-05]"""
+
+        assert repr(c) == exp
+
+        c = Categorical(idx.append(idx), categories=idx)
+        exp = """[2011-01, 2011-02, 2011-03, 2011-04, 2011-05, 2011-01, 2011-02, 2011-03, 2011-04, 2011-05]
+Categories (5, period[M]): [2011-01, 2011-02, 2011-03, 2011-04, 2011-05]"""  # noqa
+
+        assert repr(c) == exp
+
+    def test_categorical_repr_period_ordered(self):
+        idx = period_range("2011-01-01 09:00", freq="H", periods=5)
+        c = Categorical(idx, ordered=True)
+        exp = """[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00]
+Categories (5, period[H]): [2011-01-01 09:00 < 2011-01-01 10:00 < 2011-01-01 11:00 < 2011-01-01 12:00 <
+                            2011-01-01 13:00]"""  # noqa
+
+        assert repr(c) == exp
+
+        c = Categorical(idx.append(idx), categories=idx, ordered=True)
+        exp = """[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00, 2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00]
+Categories (5, period[H]): [2011-01-01 09:00 < 2011-01-01 10:00 < 2011-01-01 11:00 < 2011-01-01 12:00 <
+                            2011-01-01 13:00]"""  # noqa
+
+        assert repr(c) == exp
+
+        idx = period_range("2011-01", freq="M", periods=5)
+        c = Categorical(idx, ordered=True)
+        exp = """[2011-01, 2011-02, 2011-03, 2011-04, 2011-05]
+Categories (5, period[M]): [2011-01 < 2011-02 < 2011-03 < 2011-04 < 2011-05]"""
+
+        assert repr(c) == exp
+
+        c = Categorical(idx.append(idx), categories=idx, ordered=True)
+        exp = """[2011-01, 2011-02, 2011-03, 2011-04, 2011-05, 2011-01, 2011-02, 2011-03, 2011-04, 2011-05]
+Categories (5, period[M]): [2011-01 < 2011-02 < 2011-03 < 2011-04 < 2011-05]"""  # noqa
+
+        assert repr(c) == exp
+
+    def test_categorical_repr_timedelta(self):
+        idx = timedelta_range("1 days", periods=5)
+        c = Categorical(idx)
+        exp = """[1 days, 2 days, 3 days, 4 days, 5 days]
+Categories (5, timedelta64[ns]): [1 days, 2 days, 3 days, 4 days, 5 days]"""
+
+        assert repr(c) == exp
+
+        c = Categorical(idx.append(idx), categories=idx)
+        exp = """[1 days, 2 days, 3 days, 4 days, 5 days, 1 days, 2 days, 3 days, 4 days, 5 days]
+Categories (5, timedelta64[ns]): [1 days, 2 days, 3 days, 4 days, 5 days]"""  # noqa
+
+        assert repr(c) == exp
+
+        idx = timedelta_range("1 hours", periods=20)
+        c = Categorical(idx)
+        exp = """[0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00, 3 days 01:00:00, 4 days 01:00:00, ..., 15 days 01:00:00, 16 days 01:00:00, 17 days 01:00:00, 18 days 01:00:00, 19 days 01:00:00]
+Length: 20
+Categories (20, timedelta64[ns]): [0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00,
+                                   3 days 01:00:00, ..., 16 days 01:00:00, 17 days 01:00:00,
+                                   18 days 01:00:00, 19 days 01:00:00]"""  # noqa
+
+        assert repr(c) == exp
+
+        c = Categorical(idx.append(idx), categories=idx)
+        exp = """[0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00, 3 days 01:00:00, 4 days 01:00:00, ..., 15 days 01:00:00, 16 days 01:00:00, 17 days 01:00:00, 18 days 01:00:00, 19 days 01:00:00]
+Length: 40
+Categories (20, timedelta64[ns]): [0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00,
+                                   3 days 01:00:00, ..., 16 days 01:00:00, 17 days 01:00:00,
+                                   18 days 01:00:00, 19 days 01:00:00]"""  # noqa
+
+        assert repr(c) == exp
+
+    def test_categorical_repr_timedelta_ordered(self):
+        idx = timedelta_range("1 days", periods=5)
+        c = Categorical(idx, ordered=True)
+        exp = """[1 days, 2 days, 3 days, 4 days, 5 days]
+Categories (5, timedelta64[ns]): [1 days < 2 days < 3 days < 4 days < 5 days]"""  # noqa
+
+        assert repr(c) == exp
+
+        c = Categorical(idx.append(idx), categories=idx, ordered=True)
+        exp = """[1 days, 2 days, 3 days, 4 days, 5 days, 1 days, 2 days, 3 days, 4 days, 5 days]
+Categories (5, timedelta64[ns]): [1 days < 2 days < 3 days < 4 days < 5 days]"""  # noqa
+
+        assert repr(c) == exp
+
+        idx = timedelta_range("1 hours", periods=20)
+        c = Categorical(idx, ordered=True)
+        exp = """[0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00, 3 days 01:00:00, 4 days 01:00:00, ..., 15 days 01:00:00, 16 days 01:00:00, 17 days 01:00:00, 18 days 01:00:00, 19 days 01:00:00]
+Length: 20
+Categories (20, timedelta64[ns]): [0 days 01:00:00 < 1 days 01:00:00 < 2 days 01:00:00 <
+                                   3 days 01:00:00 ... 16 days 01:00:00 < 17 days 01:00:00 <
+                                   18 days 01:00:00 < 19 days 01:00:00]"""  # noqa
+
+        assert repr(c) == exp
+
+        c = Categorical(idx.append(idx), categories=idx, ordered=True)
+        exp = """[0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00, 3 days 01:00:00, 4 days 01:00:00, ..., 15 days 01:00:00, 16 days 01:00:00, 17 days 01:00:00, 18 days 01:00:00, 19 days 01:00:00]
+Length: 40
+Categories (20, timedelta64[ns]): [0 days 01:00:00 < 1 days 01:00:00 < 2 days 01:00:00 <
+                                   3 days 01:00:00 ... 16 days 01:00:00 < 17 days 01:00:00 <
+                                   18 days 01:00:00 < 19 days 01:00:00]"""  # noqa
+
+        assert repr(c) == exp
+
+    def test_categorical_index_repr(self):
+        idx = CategoricalIndex(Categorical([1, 2, 3]))
+        exp = """CategoricalIndex([1, 2, 3], categories=[1, 2, 3], ordered=False, dtype='category')"""  # noqa
+        assert repr(idx) == exp
+
+        i = CategoricalIndex(Categorical(np.arange(10)))
+        exp = """CategoricalIndex([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], categories=[0, 1, 2, 3, 4, 5, 6, 7, ...], ordered=False, dtype='category')"""  # noqa
+        assert repr(i) == exp
+
+    def test_categorical_index_repr_ordered(self):
+        i = CategoricalIndex(Categorical([1, 2, 3], ordered=True))
+        exp = """CategoricalIndex([1, 2, 3], categories=[1, 2, 3], ordered=True, dtype='category')"""  # noqa
+        assert repr(i) == exp
+
+        i = CategoricalIndex(Categorical(np.arange(10), ordered=True))
+        exp = """CategoricalIndex([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], categories=[0, 1, 2, 3, 4, 5, 6, 7, ...], ordered=True, dtype='category')"""  # noqa
+        assert repr(i) == exp
+
+    def test_categorical_index_repr_datetime(self):
+        idx = date_range("2011-01-01 09:00", freq="H", periods=5)
+        i = CategoricalIndex(Categorical(idx))
+        exp = """CategoricalIndex(['2011-01-01 09:00:00', '2011-01-01 10:00:00',
+                  '2011-01-01 11:00:00', '2011-01-01 12:00:00',
+                  '2011-01-01 13:00:00'],
+                 categories=[2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00, 2011-01-01 12:00:00, 2011-01-01 13:00:00], ordered=False, dtype='category')"""  # noqa
+
+        assert repr(i) == exp
+
+        idx = date_range("2011-01-01 09:00", freq="H", periods=5, tz="US/Eastern")
+        i = CategoricalIndex(Categorical(idx))
+        exp = """CategoricalIndex(['2011-01-01 09:00:00-05:00', '2011-01-01 10:00:00-05:00',
+                  '2011-01-01 11:00:00-05:00', '2011-01-01 12:00:00-05:00',
+                  '2011-01-01 13:00:00-05:00'],
+                 categories=[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, 2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, 2011-01-01 13:00:00-05:00], ordered=False, dtype='category')"""  # noqa
+
+        assert repr(i) == exp
+
+    def test_categorical_index_repr_datetime_ordered(self):
+        idx = date_range("2011-01-01 09:00", freq="H", periods=5)
+        i = CategoricalIndex(Categorical(idx, ordered=True))
+        exp = """CategoricalIndex(['2011-01-01 09:00:00', '2011-01-01 10:00:00',
+                  '2011-01-01 11:00:00', '2011-01-01 12:00:00',
+                  '2011-01-01 13:00:00'],
+                 categories=[2011-01-01 09:00:00, 2011-01-01 10:00:00, 2011-01-01 11:00:00, 2011-01-01 12:00:00, 2011-01-01 13:00:00], ordered=True, dtype='category')"""  # noqa
+
+        assert repr(i) == exp
+
+        idx = date_range("2011-01-01 09:00", freq="H", periods=5, tz="US/Eastern")
+        i = CategoricalIndex(Categorical(idx, ordered=True))
+        exp = """CategoricalIndex(['2011-01-01 09:00:00-05:00', '2011-01-01 10:00:00-05:00',
+                  '2011-01-01 11:00:00-05:00', '2011-01-01 12:00:00-05:00',
+                  '2011-01-01 13:00:00-05:00'],
+                 categories=[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, 2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, 2011-01-01 13:00:00-05:00], ordered=True, dtype='category')"""  # noqa
+
+        assert repr(i) == exp
+
+        i = CategoricalIndex(Categorical(idx.append(idx), ordered=True))
+        exp = """CategoricalIndex(['2011-01-01 09:00:00-05:00', '2011-01-01 10:00:00-05:00',
+                  '2011-01-01 11:00:00-05:00', '2011-01-01 12:00:00-05:00',
+                  '2011-01-01 13:00:00-05:00', '2011-01-01 09:00:00-05:00',
+                  '2011-01-01 10:00:00-05:00', '2011-01-01 11:00:00-05:00',
+                  '2011-01-01 12:00:00-05:00', '2011-01-01 13:00:00-05:00'],
+                 categories=[2011-01-01 09:00:00-05:00, 2011-01-01 10:00:00-05:00, 2011-01-01 11:00:00-05:00, 2011-01-01 12:00:00-05:00, 2011-01-01 13:00:00-05:00], ordered=True, dtype='category')"""  # noqa
+
+        assert repr(i) == exp
+
+    def test_categorical_index_repr_period(self):
+        # test all length
+        idx = period_range("2011-01-01 09:00", freq="H", periods=1)
+        i = CategoricalIndex(Categorical(idx))
+        exp = """CategoricalIndex(['2011-01-01 09:00'], categories=[2011-01-01 09:00], ordered=False, dtype='category')"""  # noqa
+        assert repr(i) == exp
+
+        idx = period_range("2011-01-01 09:00", freq="H", periods=2)
+        i = CategoricalIndex(Categorical(idx))
+        exp = """CategoricalIndex(['2011-01-01 09:00', '2011-01-01 10:00'], categories=[2011-01-01 09:00, 2011-01-01 10:00], ordered=False, dtype='category')"""  # noqa
+        assert repr(i) == exp
+
+        idx = period_range("2011-01-01 09:00", freq="H", periods=3)
+        i = CategoricalIndex(Categorical(idx))
+        exp = """CategoricalIndex(['2011-01-01 09:00', '2011-01-01 10:00', '2011-01-01 11:00'], categories=[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00], ordered=False, dtype='category')"""  # noqa
+        assert repr(i) == exp
+
+        idx = period_range("2011-01-01 09:00", freq="H", periods=5)
+        i = CategoricalIndex(Categorical(idx))
+        exp = """CategoricalIndex(['2011-01-01 09:00', '2011-01-01 10:00', '2011-01-01 11:00',
+                  '2011-01-01 12:00', '2011-01-01 13:00'],
+                 categories=[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00], ordered=False, dtype='category')"""  # noqa
+
+        assert repr(i) == exp
+
+        i = CategoricalIndex(Categorical(idx.append(idx)))
+        exp = """CategoricalIndex(['2011-01-01 09:00', '2011-01-01 10:00', '2011-01-01 11:00',
+                  '2011-01-01 12:00', '2011-01-01 13:00', '2011-01-01 09:00',
+                  '2011-01-01 10:00', '2011-01-01 11:00', '2011-01-01 12:00',
+                  '2011-01-01 13:00'],
+                 categories=[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00], ordered=False, dtype='category')"""  # noqa
+
+        assert repr(i) == exp
+
+        idx = period_range("2011-01", freq="M", periods=5)
+        i = CategoricalIndex(Categorical(idx))
+        exp = """CategoricalIndex(['2011-01', '2011-02', '2011-03', '2011-04', '2011-05'], categories=[2011-01, 2011-02, 2011-03, 2011-04, 2011-05], ordered=False, dtype='category')"""  # noqa
+        assert repr(i) == exp
+
+    def test_categorical_index_repr_period_ordered(self):
+        idx = period_range("2011-01-01 09:00", freq="H", periods=5)
+        i = CategoricalIndex(Categorical(idx, ordered=True))
+        exp = """CategoricalIndex(['2011-01-01 09:00', '2011-01-01 10:00', '2011-01-01 11:00',
+                  '2011-01-01 12:00', '2011-01-01 13:00'],
+                 categories=[2011-01-01 09:00, 2011-01-01 10:00, 2011-01-01 11:00, 2011-01-01 12:00, 2011-01-01 13:00], ordered=True, dtype='category')"""  # noqa
+
+        assert repr(i) == exp
+
+        idx = period_range("2011-01", freq="M", periods=5)
+        i = CategoricalIndex(Categorical(idx, ordered=True))
+        exp = """CategoricalIndex(['2011-01', '2011-02', '2011-03', '2011-04', '2011-05'], categories=[2011-01, 2011-02, 2011-03, 2011-04, 2011-05], ordered=True, dtype='category')"""  # noqa
+        assert repr(i) == exp
+
+    def test_categorical_index_repr_timedelta(self):
+        idx = timedelta_range("1 days", periods=5)
+        i = CategoricalIndex(Categorical(idx))
+        exp = """CategoricalIndex(['1 days', '2 days', '3 days', '4 days', '5 days'], categories=[1 days 00:00:00, 2 days 00:00:00, 3 days 00:00:00, 4 days 00:00:00, 5 days 00:00:00], ordered=False, dtype='category')"""  # noqa
+        assert repr(i) == exp
+
+        idx = timedelta_range("1 hours", periods=10)
+        i = CategoricalIndex(Categorical(idx))
+        exp = """CategoricalIndex(['0 days 01:00:00', '1 days 01:00:00', '2 days 01:00:00',
+                  '3 days 01:00:00', '4 days 01:00:00', '5 days 01:00:00',
+                  '6 days 01:00:00', '7 days 01:00:00', '8 days 01:00:00',
+                  '9 days 01:00:00'],
+                 categories=[0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00, 3 days 01:00:00, 4 days 01:00:00, 5 days 01:00:00, 6 days 01:00:00, 7 days 01:00:00, ...], ordered=False, dtype='category')"""  # noqa
+
+        assert repr(i) == exp
+
+    def test_categorical_index_repr_timedelta_ordered(self):
+        idx = timedelta_range("1 days", periods=5)
+        i = CategoricalIndex(Categorical(idx, ordered=True))
+        exp = """CategoricalIndex(['1 days', '2 days', '3 days', '4 days', '5 days'], categories=[1 days 00:00:00, 2 days 00:00:00, 3 days 00:00:00, 4 days 00:00:00, 5 days 00:00:00], ordered=True, dtype='category')"""  # noqa
+        assert repr(i) == exp
+
+        idx = timedelta_range("1 hours", periods=10)
+        i = CategoricalIndex(Categorical(idx, ordered=True))
+        exp = """CategoricalIndex(['0 days 01:00:00', '1 days 01:00:00', '2 days 01:00:00',
+                  '3 days 01:00:00', '4 days 01:00:00', '5 days 01:00:00',
+                  '6 days 01:00:00', '7 days 01:00:00', '8 days 01:00:00',
+                  '9 days 01:00:00'],
+                 categories=[0 days 01:00:00, 1 days 01:00:00, 2 days 01:00:00, 3 days 01:00:00, 4 days 01:00:00, 5 days 01:00:00, 6 days 01:00:00, 7 days 01:00:00, ...], ordered=True, dtype='category')"""  # noqa
+
+        assert repr(i) == exp

venv/lib/python3.6/site-packages/pandas/tests/arrays/categorical/test_sorting.py

@@ -0,0 +1,124 @@
+import numpy as np
+import pytest
+
+from pandas import Categorical, Index
+import pandas.util.testing as tm
+
+
+class TestCategoricalSort:
+    def test_argsort(self):
+        c = Categorical([5, 3, 1, 4, 2], ordered=True)
+
+        expected = np.array([2, 4, 1, 3, 0])
+        tm.assert_numpy_array_equal(
+            c.argsort(ascending=True), expected, check_dtype=False
+        )
+
+        expected = expected[::-1]
+        tm.assert_numpy_array_equal(
+            c.argsort(ascending=False), expected, check_dtype=False
+        )
+
+    def test_numpy_argsort(self):
+        c = Categorical([5, 3, 1, 4, 2], ordered=True)
+
+        expected = np.array([2, 4, 1, 3, 0])
+        tm.assert_numpy_array_equal(np.argsort(c), expected, check_dtype=False)
+
+        tm.assert_numpy_array_equal(
+            np.argsort(c, kind="mergesort"), expected, check_dtype=False
+        )
+
+        msg = "the 'axis' parameter is not supported"
+        with pytest.raises(ValueError, match=msg):
+            np.argsort(c, axis=0)
+
+        msg = "the 'order' parameter is not supported"
+        with pytest.raises(ValueError, match=msg):
+            np.argsort(c, order="C")
+
+    def test_sort_values(self):
+
+        # unordered cats are sortable
+        cat = Categorical(["a", "b", "b", "a"], ordered=False)
+        cat.sort_values()
+
+        cat = Categorical(["a", "c", "b", "d"], ordered=True)
+
+        # sort_values
+        res = cat.sort_values()
+        exp = np.array(["a", "b", "c", "d"], dtype=object)
+        tm.assert_numpy_array_equal(res.__array__(), exp)
+        tm.assert_index_equal(res.categories, cat.categories)
+
+        cat = Categorical(
+            ["a", "c", "b", "d"], categories=["a", "b", "c", "d"], ordered=True
+        )
+        res = cat.sort_values()
+        exp = np.array(["a", "b", "c", "d"], dtype=object)
+        tm.assert_numpy_array_equal(res.__array__(), exp)
+        tm.assert_index_equal(res.categories, cat.categories)
+
+        res = cat.sort_values(ascending=False)
+        exp = np.array(["d", "c", "b", "a"], dtype=object)
+        tm.assert_numpy_array_equal(res.__array__(), exp)
+        tm.assert_index_equal(res.categories, cat.categories)
+
+        # sort (inplace order)
+        cat1 = cat.copy()
+        cat1.sort_values(inplace=True)
+        exp = np.array(["a", "b", "c", "d"], dtype=object)
+        tm.assert_numpy_array_equal(cat1.__array__(), exp)
+        tm.assert_index_equal(res.categories, cat.categories)
+
+        # reverse
+        cat = Categorical(["a", "c", "c", "b", "d"], ordered=True)
+        res = cat.sort_values(ascending=False)
+        exp_val = np.array(["d", "c", "c", "b", "a"], dtype=object)
+        exp_categories = Index(["a", "b", "c", "d"])
+        tm.assert_numpy_array_equal(res.__array__(), exp_val)
+        tm.assert_index_equal(res.categories, exp_categories)
+
+    def test_sort_values_na_position(self):
+        # see gh-12882
+        cat = Categorical([5, 2, np.nan, 2, np.nan], ordered=True)
+        exp_categories = Index([2, 5])
+
+        exp = np.array([2.0, 2.0, 5.0, np.nan, np.nan])
+        res = cat.sort_values()  # default arguments
+        tm.assert_numpy_array_equal(res.__array__(), exp)
+        tm.assert_index_equal(res.categories, exp_categories)
+
+        exp = np.array([np.nan, np.nan, 2.0, 2.0, 5.0])
+        res = cat.sort_values(ascending=True, na_position="first")
+        tm.assert_numpy_array_equal(res.__array__(), exp)
+        tm.assert_index_equal(res.categories, exp_categories)
+
+        exp = np.array([np.nan, np.nan, 5.0, 2.0, 2.0])
+        res = cat.sort_values(ascending=False, na_position="first")
+        tm.assert_numpy_array_equal(res.__array__(), exp)
+        tm.assert_index_equal(res.categories, exp_categories)
+
+        exp = np.array([2.0, 2.0, 5.0, np.nan, np.nan])
+        res = cat.sort_values(ascending=True, na_position="last")
+        tm.assert_numpy_array_equal(res.__array__(), exp)
+        tm.assert_index_equal(res.categories, exp_categories)
+
+        exp = np.array([5.0, 2.0, 2.0, np.nan, np.nan])
+        res = cat.sort_values(ascending=False, na_position="last")
+        tm.assert_numpy_array_equal(res.__array__(), exp)
+        tm.assert_index_equal(res.categories, exp_categories)
+
+        cat = Categorical(["a", "c", "b", "d", np.nan], ordered=True)
+        res = cat.sort_values(ascending=False, na_position="last")
+        exp_val = np.array(["d", "c", "b", "a", np.nan], dtype=object)
+        exp_categories = Index(["a", "b", "c", "d"])
+        tm.assert_numpy_array_equal(res.__array__(), exp_val)
+        tm.assert_index_equal(res.categories, exp_categories)
+
+        cat = Categorical(["a", "c", "b", "d", np.nan], ordered=True)
+        res = cat.sort_values(ascending=False, na_position="first")
+        exp_val = np.array([np.nan, "d", "c", "b", "a"], dtype=object)
+        exp_categories = Index(["a", "b", "c", "d"])
+        tm.assert_numpy_array_equal(res.__array__(), exp_val)
+        tm.assert_index_equal(res.categories, exp_categories)

venv/lib/python3.6/site-packages/pandas/tests/arrays/categorical/test_subclass.py

@@ -0,0 +1,22 @@
+from pandas import Categorical
+import pandas.util.testing as tm
+
+
+class TestCategoricalSubclassing:
+    def test_constructor(self):
+        sc = tm.SubclassedCategorical(["a", "b", "c"])
+        assert isinstance(sc, tm.SubclassedCategorical)
+        tm.assert_categorical_equal(sc, Categorical(["a", "b", "c"]))
+
+    def test_from_codes(self):
+        sc = tm.SubclassedCategorical.from_codes([1, 0, 2], ["a", "b", "c"])
+        assert isinstance(sc, tm.SubclassedCategorical)
+        exp = Categorical.from_codes([1, 0, 2], ["a", "b", "c"])
+        tm.assert_categorical_equal(sc, exp)
+
+    def test_map(self):
+        sc = tm.SubclassedCategorical(["a", "b", "c"])
+        res = sc.map(lambda x: x.upper())
+        assert isinstance(res, tm.SubclassedCategorical)
+        exp = Categorical(["A", "B", "C"])
+        tm.assert_categorical_equal(res, exp)

venv/lib/python3.6/site-packages/pandas/tests/arrays/categorical/test_warnings.py

@@ -0,0 +1,29 @@
+import pytest
+
+import pandas as pd
+import pandas.util.testing as tm
+
+
+class TestCategoricalWarnings:
+    def test_tab_complete_warning(self, ip):
+        # https://github.com/pandas-dev/pandas/issues/16409
+        pytest.importorskip("IPython", minversion="6.0.0")
+        from IPython.core.completer import provisionalcompleter
+
+        code = "import pandas as pd; c = Categorical([])"
+        ip.run_code(code)
+        with tm.assert_produces_warning(None):
+            with provisionalcompleter("ignore"):
+                list(ip.Completer.completions("c.", 1))
+
+    def test_CategoricalAccessor_categorical_deprecation(self):
+        with tm.assert_produces_warning(FutureWarning):
+            pd.Series(["a", "b"], dtype="category").cat.categorical
+
+    def test_CategoricalAccessor_name_deprecation(self):
+        with tm.assert_produces_warning(FutureWarning):
+            pd.Series(["a", "b"], dtype="category").cat.name
+
+    def test_CategoricalAccessor_index_deprecation(self):
+        with tm.assert_produces_warning(FutureWarning):
+            pd.Series(["a", "b"], dtype="category").cat.index