move doctest to pytest for python3.5/3.6 compatibility

databricks/koalas/indexes.py

@@ -463,54 +463,7 @@ def to_pandas(self) -> pd.MultiIndex:
     # TODO: add 'name' parameter after pd.MultiIndex.name is implemented
     def copy(self):
         """
-        Make a copy of this object. name sets those attributes on the new object.
-
-        Examples
-        --------
-        >>> midx = pd.MultiIndex([['a', 'b', 'c'],
-        ...                       ['lama', 'cow', 'falcon'],
-        ...                       ['speed', 'weight', 'length']],
-        ...                      [[0, 0, 0, 0, 0, 0, 1, 1, 1],
-        ...                       [0, 0, 0, 1, 1, 1, 2, 2, 2],
-        ...                       [0, 0, 0, 0, 1, 2, 0, 1, 2]]
-        ...  )
-        >>> s = ks.Series([45, 200, 1.2, 30, 250, 1.5, 320, 1, 0.3],
-        ...              index=midx)
-        >>> s
-        a  lama    speed      45.0
-                   speed     200.0
-                   speed       1.2
-           cow     speed      30.0
-                   weight    250.0
-                   length      1.5
-        b  falcon  speed     320.0
-                   weight      1.0
-                   length      0.3
-        Name: 0, dtype: float64
-
-        >>> s.index
-        MultiIndex([('a',   'lama',  'speed'),
-                    ('a',   'lama',  'speed'),
-                    ('a',   'lama',  'speed'),
-                    ('a',    'cow',  'speed'),
-                    ('a',    'cow', 'weight'),
-                    ('a',    'cow', 'length'),
-                    ('b', 'falcon',  'speed'),
-                    ('b', 'falcon', 'weight'),
-                    ('b', 'falcon', 'length')],
-                   )
-
-        >>> s.index.copy()
-        MultiIndex([('a',   'lama',  'speed'),
-                    ('a',   'lama',  'speed'),
-                    ('a',   'lama',  'speed'),
-                    ('a',    'cow',  'speed'),
-                    ('a',    'cow', 'weight'),
-                    ('a',    'cow', 'length'),
-                    ('b', 'falcon',  'speed'),
-                    ('b', 'falcon', 'weight'),
-                    ('b', 'falcon', 'length')],
-                   )
+        Make a copy of this object.
         """
         internal = self._kdf._internal.copy()
         result = MultiIndex(ks.DataFrame(internal))

databricks/koalas/tests/test_indexes.py

@@ -140,6 +140,14 @@ def test_multi_index_names(self):
         with self.assertRaises(PandasNotImplementedError):
             kidx.name = 'renamed'
 
+    def test_multi_index_copy(self):
+        arrays = [[1, 1, 2, 2], ['red', 'blue', 'red', 'blue']]
+        idx = pd.MultiIndex.from_arrays(arrays, names=('number', 'color'))
+        pdf = pd.DataFrame(np.random.randn(4, 5), idx)
+        kdf = ks.from_pandas(pdf)
+
+        self.assert_eq(kdf.index.copy(), pdf.index.copy())
+
     def test_missing(self):
         kdf = ks.DataFrame({'a': [1, 2, 3], 'b': [4, 5, 6], 'c': [7, 8, 9]})