text: # -*- coding: utf-8 -*-
  
  
  import numpy as np
  import pandas as pd
  import pandas.util.testing as tm
  import pytest
  from pandas import CategoricalIndex, Index, MultiIndex
  from pandas.compat import range
  
  
  def assert_matching(actual, expected, check_dtype=False):
      # avoid specifying internal representation
      # as much as possible
      assert len(actual) == len(expected)
      for act, exp in zip(actual, expected):
          act = np.asarray(act)
          exp = np.asarray(exp)
          tm.assert_numpy_array_equal(act, exp, check_dtype=check_dtype)
  
  
  def test_get_level_number_integer(idx):
      idx.names = [1, 0]
      assert idx._get_level_number(1) == 0
      assert idx._get_level_number(0) == 1
      pytest.raises(IndexError, idx._get_level_number, 2)
      tm.assert_raises_regex(KeyError, 'Level fourth not found',
                             idx._get_level_number, 'fourth')
  
  
  def test_get_level_values(idx):
      result = idx.get_level_values(0)
      expected = Index(['foo', 'foo', 'bar', 'baz', 'qux', 'qux'],
                       name='first')
      tm.assert_index_equal(result, expected)
      assert result.name == 'first'
  
      result = idx.get_level_values('first')
      expected = idx.get_level_values(0)
      tm.assert_index_equal(result, expected)
  
      # GH 10460
      index = MultiIndex(
          levels=[CategoricalIndex(['A', 'B']),
                  CategoricalIndex([1, 2, 3])],
          labels=[np.array([0, 0, 0, 1, 1, 1]),
                  np.array([0, 1, 2, 0, 1, 2])])
  
      exp = CategoricalIndex(['A', 'A', 'A', 'B', 'B', 'B'])
      tm.assert_index_equal(index.get_level_values(0), exp)
      exp = CategoricalIndex([1, 2, 3, 1, 2, 3])
      tm.assert_index_equal(index.get_level_values(1), exp)
  
  
  def test_get_value_duplicates():
      index = MultiIndex(levels=[['D', 'B', 'C'],
                                 [0, 26, 27, 37, 57, 67, 75, 82]],
                         labels=[[0, 0, 0, 1, 2, 2, 2, 2, 2, 2],
                                 [1, 3, 4, 6, 0, 2, 2, 3, 5, 7]],
                         names=['tag', 'day'])
  
      assert index.get_loc('D') == slice(0, 3)
      with pytest.raises(KeyError):
          index._engine.get_value(np.array([]), 'D')
  
  
  def test_get_level_values_all_na():
      # GH 17924 when level entirely consists of nan
      arrays = [[np.nan, np.nan, np.nan], ['a', np.nan, 1]]
      index = pd.MultiIndex.from_arrays(arrays)
      result = index.get_level_values(0)
      expected = pd.Index([np.nan, np.nan, np.nan], dtype=np.float64)
      tm.assert_index_equal(result, expected)
  
      result = index.get_level_values(1)
      expected = pd.Index(['a', np.nan, 1], dtype=object)
      tm.assert_index_equal(result, expected)
  
  
  def test_get_level_values_int_with_na():
      # GH 17924
      arrays = [['a', 'b', 'b'], [1, np.nan, 2]]
      index = pd.MultiIndex.from_arrays(arrays)
      result = index.get_level_values(1)
      expected = Index([1, np.nan, 2])
      tm.assert_index_equal(result, expected)
  
      arrays = [['a', 'b', 'b'], [np.nan, np.nan, 2]]
      index = pd.MultiIndex.from_arrays(arrays)
      result = index.get_level_values(1)
      expected = Index([np.nan, np.nan, 2])
      tm.assert_index_equal(result, expected)
  
  
  def test_get_level_values_na():
      arrays = [[np.nan, np.nan, np.nan], ['a', np.nan, 1]]
      index = pd.MultiIndex.from_arrays(arrays)
      result = index.get_level_values(0)
      expected = pd.Index([np.nan, np.nan, np.nan])
      tm.assert_index_equal(result, expected)
  
      result = index.get_level_values(1)
      expected = pd.Index(['a', np.nan, 1])
      tm.assert_index_equal(result, expected)
  
      arrays = [['a', 'b', 'b'], pd.DatetimeIndex([0, 1, pd.NaT])]
      index = pd.MultiIndex.from_arrays(arrays)
      result = index.get_level_values(1)
      expected = pd.DatetimeIndex([0, 1, pd.NaT])
      tm.assert_index_equal(result, expected)
  
      arrays = [[], []]
      index = pd.MultiIndex.from_arrays(arrays)
      result = index.get_level_values(0)
      expected = pd.Index([], dtype=object)
      tm.assert_index_equal(result, expected)
  
  
  def test_set_name_methods(idx, index_names):
      # so long as these are synonyms, we don't need to test set_names
      assert idx.rename == idx.set_names
      new_names = [name + "SUFFIX" for name in index_names]
      ind = idx.set_names(new_names)
      assert idx.names == index_names
      assert ind.names == new_names
      with tm.assert_raises_regex(ValueError, "^Length"):
          ind.set_names(new_names + new_names)
      new_names2 = [name + "SUFFIX2" for name in new_names]
      res = ind.set_names(new_names2, inplace=True)
      assert res is None
      assert ind.names == new_names2
  
      # set names for specific level (# GH7792)
      ind = idx.set_names(new_names[0], level=0)
      assert idx.names == index_names
      assert ind.names == [new_names[0], index_names[1]]
  
      res = ind.set_names(new_names2[0], level=0, inplace=True)
      assert res is None
      assert ind.names == [new_names2[0], index_names[1]]
  
      # set names for multiple levels
      ind = idx.set_names(new_names, level=[0, 1])
      assert idx.names == index_names
      assert ind.names == new_names
  
      res = ind.set_names(new_names2, level=[0, 1], inplace=True)
      assert res is None
      assert ind.names == new_names2
  
  
  def test_set_levels_labels_directly(idx):
      # setting levels/labels directly raises AttributeError
  
      levels = idx.levels
      new_levels = [[lev + 'a' for lev in level] for level in levels]
  
      labels = idx.labels
      major_labels, minor_labels = labels
      major_labels = [(x + 1) % 3 for x in major_labels]
      minor_labels = [(x + 1) % 1 for x in minor_labels]
      new_labels = [major_labels, minor_labels]
  
      with pytest.raises(AttributeError):
          idx.levels = new_levels
  
      with pytest.raises(AttributeError):
          idx.labels = new_labels
  
  
  def test_set_levels(idx):
      # side note - you probably wouldn't want to use levels and labels
      # directly like this - but it is possible.
      levels = idx.levels
      new_levels = [[lev + 'a' for lev in level] for level in levels]
  
      # level changing [w/o mutation]
      ind2 = idx.set_levels(new_levels)
      assert_matching(ind2.levels, new_levels)
      assert_matching(idx.levels, levels)
  
      # level changing [w/ mutation]
      ind2 = idx.copy()
      inplace_return = ind2.set_levels(new_levels, inplace=True)
      assert inplace_return is None
      assert_matching(ind2.levels, new_levels)
  
      # level changing specific level [w/o mutation]
      ind2 = idx.set_levels(new_levels[0], level=0)
      assert_matching(ind2.levels, [new_levels[0], levels[1]])
      assert_matching(idx.levels, levels)
  
      ind2 = idx.set_levels(new_levels[1], level=1)
      assert_matching(ind2.levels, [levels[0], new_levels[1]])
      assert_matching(idx.levels, levels)
  
      # level changing multiple levels [w/o mutation]
      ind2 = idx.set_levels(new_levels, level=[0, 1])
      assert_matching(ind2.levels, new_levels)
      assert_matching(idx.levels, levels)
  
      # level changing specific level [w/ mutation]
      ind2 = idx.copy()
      inplace_return = ind2.set_levels(new_levels[0], level=0, inplace=True)
      assert inplace_return is None
      assert_matching(ind2.levels, [new_levels[0], levels[1]])
      assert_matching(idx.levels, levels)
  
      ind2 = idx.copy()
      inplace_return = ind2.set_levels(new_levels[1], level=1, inplace=True)
      assert inplace_return is None
      assert_matching(ind2.levels, [levels[0], new_levels[1]])
      assert_matching(idx.levels, levels)
  
      # level changing multiple levels [w/ mutation]
      ind2 = idx.copy()
      inplace_return = ind2.set_levels(new_levels, level=[0, 1],
                                       inplace=True)
      assert inplace_return is None
      assert_matching(ind2.levels, new_levels)
      assert_matching(idx.levels, levels)
  
      # illegal level changing should not change levels
      # GH 13754
      original_index = idx.copy()
      for inplace in [True, False]:
          with tm.assert_raises_regex(ValueError, "^On"):
              idx.set_levels(['c'], level=0, inplace=inplace)
          assert_matching(idx.levels, original_index.levels,
                          check_dtype=True)
  
          with tm.assert_raises_regex(ValueError, "^On"):
              idx.set_labels([0, 1, 2, 3, 4, 5], level=0,
                             inplace=inplace)
          assert_matching(idx.labels, original_index.labels,
                          check_dtype=True)
  
          with tm.assert_raises_regex(TypeError, "^Levels"):
              idx.set_levels('c', level=0, inplace=inplace)
          assert_matching(idx.levels, original_index.levels,
                          check_dtype=True)
  
          with tm.assert_raises_regex(TypeError, "^Labels"):
              idx.set_labels(1, level=0, inplace=inplace)
          assert_matching(idx.labels, original_index.labels,
                          check_dtype=True)
  
  
  def test_set_labels(idx):
      # side note - you probably wouldn't want to use levels and labels
      # directly like this - but it is possible.
      labels = idx.labels
      major_labels, minor_labels = labels
      major_labels = [(x + 1) % 3 for x in major_labels]
      minor_labels = [(x + 1) % 1 for x in minor_labels]
      new_labels = [major_labels, minor_labels]
  
      # label changing [w/o mutation]
      ind2 = idx.set_labels(new_labels)
      assert_matching(ind2.labels, new_labels)
      assert_matching(idx.labels, labels)
  
      # label changing [w/ mutation]
      ind2 = idx.copy()
      inplace_return = ind2.set_labels(new_labels, inplace=True)
      assert inplace_return is None
      assert_matching(ind2.labels, new_labels)
  
      # label changing specific level [w/o mutation]
      ind2 = idx.set_labels(new_labels[0], level=0)
      assert_matching(ind2.labels, [new_labels[0], labels[1]])
      assert_matching(idx.labels, labels)
  
      ind2 = idx.set_labels(new_labels[1], level=1)
      assert_matching(ind2.labels, [labels[0], new_labels[1]])
      assert_matching(idx.labels, labels)
  
      # label changing multiple levels [w/o mutation]
      ind2 = idx.set_labels(new_labels, level=[0, 1])
      assert_matching(ind2.labels, new_labels)
      assert_matching(idx.labels, labels)
  
      # label changing specific level [w/ mutation]
      ind2 = idx.copy()
      inplace_return = ind2.set_labels(new_labels[0], level=0, inplace=True)
      assert inplace_return is None
      assert_matching(ind2.labels, [new_labels[0], labels[1]])
      assert_matching(idx.labels, labels)
  
      ind2 = idx.copy()
      inplace_return = ind2.set_labels(new_labels[1], level=1, inplace=True)
      assert inplace_return is None
      assert_matching(ind2.labels, [labels[0], new_labels[1]])
      assert_matching(idx.labels, labels)
  
      # label changing multiple levels [w/ mutation]
      ind2 = idx.copy()
      inplace_return = ind2.set_labels(new_labels, level=[0, 1],
                                       inplace=True)
      assert inplace_return is None
      assert_matching(ind2.labels, new_labels)
      assert_matching(idx.labels, labels)
  
      # label changing for levels of different magnitude of categories
      ind = pd.MultiIndex.from_tuples([(0, i) for i in range(130)])
      new_labels = range(129, -1, -1)
      expected = pd.MultiIndex.from_tuples(
          [(0, i) for i in new_labels])
  
      # [w/o mutation]
      result = ind.set_labels(labels=new_labels, level=1)
      assert result.equals(expected)
  
      # [w/ mutation]
      result = ind.copy()
      result.set_labels(labels=new_labels, level=1, inplace=True)
      assert result.equals(expected)
  
  
  def test_set_levels_labels_names_bad_input(idx):
      levels, labels = idx.levels, idx.labels
      names = idx.names
  
      with tm.assert_raises_regex(ValueError, 'Length of levels'):
          idx.set_levels([levels[0]])
  
      with tm.assert_raises_regex(ValueError, 'Length of labels'):
          idx.set_labels([labels[0]])
  
      with tm.assert_raises_regex(ValueError, 'Length of names'):
          idx.set_names([names[0]])
  
      # shouldn't scalar data error, instead should demand list-like
      with tm.assert_raises_regex(TypeError, 'list of lists-like'):
          idx.set_levels(levels[0])
  
      # shouldn't scalar data error, instead should demand list-like
      with tm.assert_raises_regex(TypeError, 'list of lists-like'):
          idx.set_labels(labels[0])
  
      # shouldn't scalar data error, instead should demand list-like
      with tm.assert_raises_regex(TypeError, 'list-like'):
          idx.set_names(names[0])
  
      # should have equal lengths
      with tm.assert_raises_regex(TypeError, 'list of lists-like'):
          idx.set_levels(levels[0], level=[0, 1])
  
      with tm.assert_raises_regex(TypeError, 'list-like'):
          idx.set_levels(levels, level=0)
  
      # should have equal lengths
      with tm.assert_raises_regex(TypeError, 'list of lists-like'):
          idx.set_labels(labels[0], level=[0, 1])
  
      with tm.assert_raises_regex(TypeError, 'list-like'):
          idx.set_labels(labels, level=0)
  
      # should have equal lengths
      with tm.assert_raises_regex(ValueError, 'Length of names'):
          idx.set_names(names[0], level=[0, 1])
  
      with tm.assert_raises_regex(TypeError, 'Names must be a'):
          idx.set_names(names, level=0)
  
  
  @pytest.mark.parametrize('inplace', [True, False])
  def test_set_names_with_nlevel_1(inplace):
      # GH 21149
      # Ensure that .set_names for MultiIndex with
      # nlevels == 1 does not raise any errors
      expected = pd.MultiIndex(levels=[[0, 1]],
                               labels=[[0, 1]],
                               names=['first'])
      m = pd.MultiIndex.from_product([[0, 1]])
      result = m.set_names('first', level=0, inplace=inplace)
  
      if inplace:
          result = m
  
      tm.assert_index_equal(result, expected)
  
  
  @pytest.mark.parametrize('ordered', [True, False])
  def test_set_levels_categorical(ordered):
      # GH13854
      index = MultiIndex.from_arrays([list("xyzx"), [0, 1, 2, 3]])
  
      cidx = CategoricalIndex(list("bac"), ordered=ordered)
      result = index.set_levels(cidx, 0)
      expected = MultiIndex(levels=[cidx, [0, 1, 2, 3]],
                            labels=index.labels)
      tm.assert_index_equal(result, expected)
  
      result_lvl = result.get_level_values(0)
      expected_lvl = CategoricalIndex(list("bacb"),
                                      categories=cidx.categories,
                                      ordered=cidx.ordered)
      tm.assert_index_equal(result_lvl, expected_lvl)
  
  
  def test_set_value_keeps_names():
      # motivating example from #3742
      lev1 = ['hans', 'hans', 'hans', 'grethe', 'grethe', 'grethe']
      lev2 = ['1', '2', '3'] * 2
      idx = pd.MultiIndex.from_arrays([lev1, lev2], names=['Name', 'Number'])
      df = pd.DataFrame(
          np.random.randn(6, 4),
          columns=['one', 'two', 'three', 'four'],
          index=idx)
      df = df.sort_index()
      assert df._is_copy is None
      assert df.index.names == ('Name', 'Number')
      df.at[('grethe', '4'), 'one'] = 99.34
      assert df._is_copy is None
      assert df.index.names == ('Name', 'Number')
  