CLN: Address MulitIndex Test Follow Ups in Issue #21918

pandas/tests/indexes/multi/test_astype.py

@@ -0,0 +1,16 @@
+# -*- coding: utf-8 -*-
+
+import numpy as np
+import pandas.util.testing as tm
+from pandas.util.testing import assert_copy
+
+
+def test_astype(idx):
+    expected = idx.copy()
+    actual = idx.astype('O')
+    assert_copy(actual.levels, expected.levels)
+    assert_copy(actual.labels, expected.labels)
+    assert [level.name for level in actual.levels] == list(expected.names)
+
+    with tm.assert_raises_regex(TypeError, "^Setting.*dtype.*object"):
+        idx.astype(np.dtype(int))

pandas/tests/indexes/multi/test_constructor.py

@@ -234,29 +234,31 @@ def test_from_arrays_empty():
         tm.assert_index_equal(result, expected)
 
 
-def test_from_arrays_invalid_input():
+@pytest.mark.parametrize('invalid_array', [
+    (1),
+    ([1]),
+    ([1, 2]),
+    ([[1], 2]),
+    ('a'),
+    (['a']),
+    (['a', 'b']),
+    ([['a'], 'b']),
+])
+def test_from_arrays_invalid_input(invalid_array):
     invalid_inputs = [1, [1], [1, 2], [[1], 2],
                       'a', ['a'], ['a', 'b'], [['a'], 'b']]
     for i in invalid_inputs:
         pytest.raises(TypeError, MultiIndex.from_arrays, arrays=i)
 
 
-def test_from_arrays_different_lengths():
+@pytest.mark.parametrize('idx1, idx2', [
+    pytest.param([1, 2, 3], ['a', 'b']),
+    pytest.param([], ['a', 'b']),
+    pytest.param([1, 2, 3], [])
+]
+)
+def test_from_arrays_different_lengths(idx1, idx2):
     # see gh-13599
-    idx1 = [1, 2, 3]
-    idx2 = ['a', 'b']
-    tm.assert_raises_regex(ValueError, '^all arrays must '
-                           'be same length$',
-                           MultiIndex.from_arrays, [idx1, idx2])
-
-    idx1 = []
-    idx2 = ['a', 'b']
-    tm.assert_raises_regex(ValueError, '^all arrays must '
-                           'be same length$',
-                           MultiIndex.from_arrays, [idx1, idx2])
-
-    idx1 = [1, 2, 3]
-    idx2 = []
     tm.assert_raises_regex(ValueError, '^all arrays must '
                            'be same length$',
                            MultiIndex.from_arrays, [idx1, idx2])
@@ -305,35 +307,41 @@ def test_from_tuples_index_values(idx):
     assert (result.values == idx.values).all()
 
 
-def test_from_product_empty():
+def test_from_product_empty_zero_levels():
     # 0 levels
     with tm.assert_raises_regex(
             ValueError, "Must pass non-zero number of levels/labels"):
         MultiIndex.from_product([])
 
-    # 1 level
+
+def test_from_product_empty_one_level():
     result = MultiIndex.from_product([[]], names=['A'])
     expected = pd.Index([], name='A')
     tm.assert_index_equal(result.levels[0], expected)
 
-    # 2 levels
-    l1 = [[], ['foo', 'bar', 'baz'], []]
-    l2 = [[], [], ['a', 'b', 'c']]
+
+@pytest.mark.parametrize('first, second', [
+    ([], []),
+    (['foo', 'bar', 'baz'], []),
+    ([], ['a', 'b', 'c']),
+])
+def test_from_product_empty_two_levels(first, second):
     names = ['A', 'B']
-    for first, second in zip(l1, l2):
-        result = MultiIndex.from_product([first, second], names=names)
-        expected = MultiIndex(levels=[first, second],
-                              labels=[[], []], names=names)
-        tm.assert_index_equal(result, expected)
+    result = MultiIndex.from_product([first, second], names=names)
+    expected = MultiIndex(levels=[first, second],
+                          labels=[[], []], names=names)
+    tm.assert_index_equal(result, expected)
+
 
+@pytest.mark.parametrize('N', list(range(4)))
+def test_from_product_empty_three_levels(N):
     # GH12258
     names = ['A', 'B', 'C']
-    for N in range(4):
-        lvl2 = lrange(N)
-        result = MultiIndex.from_product([[], lvl2, []], names=names)
-        expected = MultiIndex(levels=[[], lvl2, []],
-                              labels=[[], [], []], names=names)
-        tm.assert_index_equal(result, expected)
+    lvl2 = lrange(N)
+    result = MultiIndex.from_product([[], lvl2, []], names=names)
+    expected = MultiIndex(levels=[[], lvl2, []],
+                          labels=[[], [], []], names=names)
+    tm.assert_index_equal(result, expected)
 
 
 def test_from_product_invalid_input():
@@ -352,19 +360,24 @@ def test_from_product_datetimeindex():
     tm.assert_numpy_array_equal(mi.values, etalon)
 
 
-def test_from_product_index_series_categorical():
+@pytest.mark.parametrize('ordered', [False, True])
+@pytest.mark.parametrize('f', [
+    lambda x: x,
+    lambda x: pd.Series(x),
+    lambda x: x.values
+])
+def test_from_product_index_series_categorical(ordered, f):
     # GH13743
     first = ['foo', 'bar']
-    for ordered in [False, True]:
-        idx = pd.CategoricalIndex(list("abcaab"), categories=list("bac"),
-                                  ordered=ordered)
-        expected = pd.CategoricalIndex(list("abcaab") + list("abcaab"),
-                                       categories=list("bac"),
-                                       ordered=ordered)
 
-        for arr in [idx, pd.Series(idx), idx.values]:
-            result = pd.MultiIndex.from_product([first, arr])
-            tm.assert_index_equal(result.get_level_values(1), expected)
+    idx = pd.CategoricalIndex(list("abcaab"), categories=list("bac"),
+                              ordered=ordered)
+    expected = pd.CategoricalIndex(list("abcaab") + list("abcaab"),
+                                   categories=list("bac"),
+                                   ordered=ordered)
+
+    result = pd.MultiIndex.from_product([first, f(idx)])
+    tm.assert_index_equal(result.get_level_values(1), expected)
 
 
 def test_from_product():
@@ -409,19 +422,28 @@ def test_create_index_existing_name(idx):
     index = idx
     index.names = ['foo', 'bar']
     result = pd.Index(index)
-    tm.assert_index_equal(
-        result, Index(Index([('foo', 'one'), ('foo', 'two'),
-                             ('bar', 'one'), ('baz', 'two'),
-                             ('qux', 'one'), ('qux', 'two')],
-                            dtype='object'),
-                      names=['foo', 'bar']))
+    expected = Index(
+        Index([
+            ('foo', 'one'), ('foo', 'two'),
+            ('bar', 'one'), ('baz', 'two'),
+            ('qux', 'one'), ('qux', 'two')],
+            dtype='object'
+        ),
+        names=['foo', 'bar']
+    )
+    tm.assert_index_equal(result, expected)
 
     result = pd.Index(index, names=['A', 'B'])
-    tm.assert_index_equal(
-        result,
-        Index(Index([('foo', 'one'), ('foo', 'two'), ('bar', 'one'),
-                     ('baz', 'two'), ('qux', 'one'), ('qux', 'two')],
-                    dtype='object'), names=['A', 'B']))
+    expected = Index(
+        Index([
+            ('foo', 'one'), ('foo', 'two'),
+            ('bar', 'one'), ('baz', 'two'),
+            ('qux', 'one'), ('qux', 'two')],
+            dtype='object'
+        ),
+        names=['A', 'B']
+    )
+    tm.assert_index_equal(result, expected)
 
 
 def test_tuples_with_name_string():

pandas/tests/indexes/multi/test_copy.py

@@ -3,8 +3,8 @@
 from copy import copy, deepcopy
 
 import pandas.util.testing as tm
-from pandas import (CategoricalIndex, IntervalIndex, MultiIndex, PeriodIndex,
-                    RangeIndex, Series, compat)
+import pytest
+from pandas import MultiIndex
 
 
 def assert_multiindex_copied(copy, original):
@@ -41,84 +41,46 @@ def test_view(idx):
     assert_multiindex_copied(i_view, idx)
 
 
-def test_copy_name(idx):
-    # gh-12309: Check that the "name" argument
-    # passed at initialization is honored.
-
-    # TODO: Remove or refactor MultiIndex not tested.
-    for name, index in compat.iteritems({'idx': idx}):
-        if isinstance(index, MultiIndex):
-            continue
-
-        first = index.__class__(index, copy=True, name='mario')
-        second = first.__class__(first, copy=False)
-
-        # Even though "copy=False", we want a new object.
-        assert first is not second
-
-        # Not using tm.assert_index_equal() since names differ.
-        assert index.equals(first)
-
-        assert first.name == 'mario'
-        assert second.name == 'mario'
-
-        s1 = Series(2, index=first)
-        s2 = Series(3, index=second[:-1])
-
-        if not isinstance(index, CategoricalIndex):
-            # See gh-13365
-            s3 = s1 * s2
-            assert s3.index.name == 'mario'
-
-
-def test_ensure_copied_data(idx):
-    # Check the "copy" argument of each Index.__new__ is honoured
-    # GH12309
-    # TODO: REMOVE THIS TEST.  MultiIndex is tested seperately as noted below.
-
-    for name, index in compat.iteritems({'idx': idx}):
-        init_kwargs = {}
-        if isinstance(index, PeriodIndex):
-            # Needs "freq" specification:
-            init_kwargs['freq'] = index.freq
-        elif isinstance(index, (RangeIndex, MultiIndex, CategoricalIndex)):
-            # RangeIndex cannot be initialized from data
-            # MultiIndex and CategoricalIndex are tested separately
-            continue
-
-        index_type = index.__class__
-        result = index_type(index.values, copy=True, **init_kwargs)
-        tm.assert_index_equal(index, result)
-        tm.assert_numpy_array_equal(index.values, result.values,
-                                    check_same='copy')
-
-        if isinstance(index, PeriodIndex):
-            # .values an object array of Period, thus copied
-            result = index_type(ordinal=index.asi8, copy=False,
-                                **init_kwargs)
-            tm.assert_numpy_array_equal(index._ndarray_values,
-                                        result._ndarray_values,
-                                        check_same='same')
-        elif isinstance(index, IntervalIndex):
-            # checked in test_interval.py
-            pass
-        else:
-            result = index_type(index.values, copy=False, **init_kwargs)
-            tm.assert_numpy_array_equal(index.values, result.values,
-                                        check_same='same')
-            tm.assert_numpy_array_equal(index._ndarray_values,
-                                        result._ndarray_values,
-                                        check_same='same')
-
-
-def test_copy_and_deepcopy(indices):
-
-    if isinstance(indices, MultiIndex):
-        return
-    for func in (copy, deepcopy):
-        idx_copy = func(indices)
-        assert idx_copy is not indices
-        assert idx_copy.equals(indices)
-
-    new_copy = indices.copy(deep=True, name="banana")
-    assert new_copy.name == "banana"
+@pytest.mark.parametrize('func', [copy, deepcopy])
+def test_copy_and_deepcopy(func):
+
+    idx = MultiIndex(
+        levels=[['foo', 'bar'], ['fizz', 'buzz']],
+        labels=[[0, 0, 0, 1], [0, 0, 1, 1]],
+        names=['first', 'second']
+    )
+    idx_copy = func(idx)
+    assert idx_copy is not idx
+    assert idx_copy.equals(idx)
+
+
+@pytest.mark.parametrize('deep', [True, False])
+def test_copy_method(deep):
+    idx = MultiIndex(
+        levels=[['foo', 'bar'], ['fizz', 'buzz']],
+        labels=[[0, 0, 0, 1], [0, 0, 1, 1]],
+        names=['first', 'second']
+    )
+    idx_copy = idx.copy(deep=deep)
+    assert idx_copy.equals(idx)
+
+
+@pytest.mark.parametrize('deep', [True, False])
+@pytest.mark.parametrize('kwarg, value', [
+    ('names', ['thrid', 'fourth']),
+    ('levels', [['foo2', 'bar2'], ['fizz2', 'buzz2']]),
+    ('labels', [[1, 0, 0, 0], [1, 1, 0, 0]])
+])
+def test_copy_method_kwargs(deep, kwarg, value):
+    # gh-12309: Check that the "name" argument as well other kwargs are honored
+    idx = MultiIndex(
+        levels=[['foo', 'bar'], ['fizz', 'buzz']],
+        labels=[[0, 0, 0, 1], [0, 0, 1, 1]],
+        names=['first', 'second']
+    )
+
+    idx_copy = idx.copy(**{kwarg: value, 'deep': deep})
+    if kwarg == 'names':
+        assert getattr(idx_copy, kwarg) == value
+    else:
+        assert list(list(i) for i in getattr(idx_copy, kwarg)) == value

pandas/tests/indexes/multi/test_format.py

@@ -100,11 +100,6 @@ def test_repr_roundtrip():
     tm.assert_index_equal(result, mi_u, exact=True)
 
 
-def test_str():
-    # tested elsewhere
-    pass
-
-
 def test_unicode_string_with_unicode():
     d = {"a": [u("\u05d0"), 2, 3], "b": [4, 5, 6], "c": [7, 8, 9]}
     idx = pd.DataFrame(d).set_index(["a", "b"]).index