def test_truediv_bool(self):
some_bool = True
with pytest.raises(TypeError):
self.df / some_bool
with pytest.raises(TypeError):
self.df.select_dtypes('str') / some_bool
with pytest.raises(TypeError):
self.df / some_bool
df1 = self.df.select_dtypes('number') / some_bool
df2 = dx.DataFrame(
{
'a': [0., nan, 5],
'b': [0, 1.5, nan],
'f': [0., 4, 5],
'g': np.zeros(3, dtype='float64'),
'h': [nan, nan, nan]
},
columns=list('abfgh'))
assert_frame_equal(df1, df2)
df1 = some_bool / self.df.select_dtypes('number')
df2 = dx.DataFrame(
{
'a': [np.inf, nan, .2],
'b': [np.inf, 1 / 1.5, nan],
'f': [np.inf, .25, .2],
'g': [np.inf] * 3,
'h': [nan, nan, nan]
},
columns=list('abfgh'))
assert_frame_equal(df1, df2)
def test_value_counts_sort_na(self):
df = dx.DataFrame(
{'AIRLINE': ['EV', 'VX', 'AA', 'UA', 'DL', 'B6', 'WN', 'AA', 'DL', 'AS', None, None],
'DAY_OF_WEEK': [2, 1, 6, 4, 5, 5, 7, 5, 1, 4, 3, 3],
'DEPARTURE_DELAY': [nan, -4.0, -1.0, -4.0, -1.0, 22.0, -3.0, 3.0, 21.0,
-2.0, nan, 22]})
df1 = df.value_counts('DAY_OF_WEEK', sort=False)
df2 = dx.DataFrame({'DAY_OF_WEEK': [1, 2, 3, 4, 5, 6, 7], 'count': [2, 1, 2, 2, 3, 1, 1]})
assert_frame_equal(df1, df2)
df1 = df.value_counts('DEPARTURE_DELAY', sort=False)
df2 = dx.DataFrame({'DEPARTURE_DELAY': [-4.0, -1.0, 22.0, -3.0, 3.0, 21.0, -2.0],
'count': [2, 2, 2, 1, 1, 1, 1]})
assert_frame_equal(df1, df2)
df1 = df.value_counts('DEPARTURE_DELAY', dropna=False)
df2 = dx.DataFrame({'DEPARTURE_DELAY': [22.0, -1.0, -4.0, nan, -2.0, 21.0, 3.0, -3.0],
'count': [2, 2, 2, 2, 1, 1, 1, 1]})
assert_frame_equal(df1, df2)
df1 = df.value_counts('AIRLINE', dropna=False)
df2 = dx.DataFrame({'AIRLINE': [None, 'DL', 'AA', 'AS', 'WN', 'B6', 'UA', 'VX', 'EV'],
'count': [2, 2, 2, 1, 1, 1, 1, 1, 1]})
assert_frame_equal(df1, df2)
df1 = df.value_counts('DEPARTURE_DELAY', dropna=False, sort=False)
df2 = dx.DataFrame({'DEPARTURE_DELAY': [nan, -4.0, -1.0, 22.0, -3.0, 3.0, 21.0, -2.0],
'count': [2, 2, 2, 2, 1, 1, 1, 1]})
assert_frame_equal(df1, df2)
def test_mod_float(self):
with pytest.raises(TypeError):
self.df % 5.
with pytest.raises(TypeError):
self.df.select_dtypes('str') % 10.
with pytest.raises(TypeError):
self.df % 'asdf'
df = dx.DataFrame(
{
'a': [6., 7, 10],
'b': [0., 2, nan],
'f': [0., 10, 3],
'g': np.zeros(3, dtype='float64'),
'h': [nan, nan, nan]
},
columns=list('abfgh'))
df1 = df % 3.
df2 = dx.DataFrame(
{
'a': [0., 1, 1],
'b': [0., 2, nan],
'f': [0., 1, 0],
'g': np.zeros(3, dtype='float64'),
'h': [nan, nan, nan]
},
columns=list('abfgh'))
assert_frame_equal(df1, df2)
def test_bfillna(self):
data = {
'a': [4, nan, nan, nan, 3, 2],
'b': [None, 'a', 'd', None, None, 'er'],
'c': [nan, nan, 5, nan, 7, nan]
}
df = de.DataFrame(data)
df1 = df.fillna(method='bfill')
df2 = de.DataFrame({
'a': [4.0, 3.0, 3.0, 3.0, 3.0, 2.0],
'b': ['a', 'a', 'd', 'er', 'er', 'er'],
'c': [5.0, 5.0, 5.0, 7.0, 7.0, nan]
})
assert_frame_equal(df1, df2)
df1 = df.fillna(method='bfill', limit=1)
df2 = de.DataFrame({
'a': [4.0, nan, nan, 3.0, 3.0, 2.0],
'b': ['a', 'a', 'd', None, 'er', 'er'],
'c': [nan, 5.0, 5.0, 7.0, 7.0, nan]
})
assert_frame_equal(df1, df2)
with pytest.raises(ValueError):
df.fillna(method='bfill', limit=0)
with pytest.raises(ValueError):
df.fillna(method='bfill', limit=1, fill_function='mean')
with pytest.raises(ValueError):
df.fillna(values=10, method='bfill')
def test_less_than_equal(self):
with pytest.raises(TypeError):
self.df <= 5
with pytest.raises(TypeError):
self.df.select_dtypes('str') <= 10
with pytest.raises(TypeError):
self.df <= 'asdf'
df = dx.DataFrame({
'a': [6, 7, 10],
'b': [0, 2, nan],
'f': [0, 10, 3],
'g': np.zeros(3, dtype='int'),
'h': [nan, nan, nan]
})
df1 = df <= 3
df2 = dx.DataFrame({
'a': [False, False, False],
'b': [True, True, False],
'f': [True, False, True],
'g': np.ones(3, dtype='bool'),
'h': [False] * 3
})
assert_frame_equal(df1, df2)
def test_drop_rows(self):
data = {'a': [0, 0, 5, 9],
'b': [0, 1.5, 8, 9],
'c': [''] + list('efs'),
'd': [False, False, True, False],
'e': [0, 20, 30, 4],
'f': ['a', nan, 'ad', 'effd'],
'g': [np.nan] * 4}
df = de.DataFrame(data)
df1 = df.drop(rows=3)
df2 = de.DataFrame({'a': [0, 0, 5],
'b': [0.0, 1.5, 8.0],
'c': ['', 'e', 'f'],
'd': [False, False, True],
'e': [0, 20, 30],
'f': ['a', None, 'ad'],
'g': [nan, nan, nan]})
assert_frame_equal(df1, df2)
with pytest.raises(IndexError):
df.drop(rows=5)
df1 = df.drop(rows=[-1, 0, -3])
df2 = de.DataFrame({'a': [5],
'b': [8.0],
'c': ['f'],
'd': [True],
'e': [30],
'f': ['ad'],
'g': [nan]})
assert_frame_equal(df1, df2)
def test_sort_values_multiple(self):
df = de.DataFrame({'a': [2, 3, nan, 6, 3, 2],
'b': [None, 'f', 'd', 'f', 'd', 'er'],
'c': [12, 444, -5.6, 5, 1, 7]})
df1 = df.sort_values(['a', 'b'], ascending=False)
df2 = de.DataFrame({'a': [6.0, 3.0, 3.0, 2.0, 2.0, nan],
'b': ['f', 'f', 'd', 'er', None, 'd'],
'c': [5.0, 444.0, 1.0, 7.0, 12.0, -5.6]})
assert_frame_equal(df1, df2)
df1 = df.sort_values(['a', 'b'], ascending=True)
df2 = de.DataFrame({'a': [2.0, 2.0, 3.0, 3.0, 6.0, nan],
'b': ['er', None, 'd', 'f', 'f', 'd'],
'c': [7.0, 12.0, 1.0, 444.0, 5.0, -5.6]})
assert_frame_equal(df1, df2)
df1 = df.sort_values(['a', 'b'], ascending=[True, False])
df2 = de.DataFrame({'a': [2.0, 2.0, 3.0, 3.0, 6.0, nan],
'b': ['er', None, 'f', 'd', 'f', 'd'],
'c': [7.0, 12.0, 444.0, 1.0, 5.0, -5.6]})
assert_frame_equal(df1, df2)
df1 = df.sort_values(['a', 'b'], ascending=[False, True])
df2 = de.DataFrame({'a': [6.0, 3.0, 3.0, 2.0, 2.0, nan],
'b': ['f', 'd', 'f', 'er', None, 'd'],
'c': [5.0, 1.0, 444.0, 7.0, 12.0, -5.6]})
assert_frame_equal(df1, df2)
df1 = df.sort_values(['b', 'a'], ascending=[False, True])
df2 = de.DataFrame({'a': [3.0, 6.0, 2.0, 3.0, nan, 2.0],
'b': ['f', 'f', 'er', 'd', 'd', None],
'c': [444.0, 5.0, 7.0, 1.0, -5.6, 12.0]})
assert_frame_equal(df1, df2)
def test_truediv_float(self):
with pytest.raises(TypeError):
self.df / 5.
with pytest.raises(TypeError):
self.df.select_dtypes('str') / 10.
with pytest.raises(TypeError):
self.df / 'asdf'
df1 = self.df.select_dtypes('number') / 2.
df2 = dx.DataFrame(
{
'a': [0, nan, 2.5],
'b': [0, .75, nan],
'f': [0, 2, 2.5],
'g': np.zeros(3),
'h': [nan, nan, nan]
},
columns=list('abfgh'))
assert_frame_equal(df1, df2)
df1 = 10. / self.df.select_dtypes('number')
df2 = dx.DataFrame(
{
'a': [np.inf, nan, 2],
'b': [np.inf, 10 / 1.5, nan],
'f': [np.inf, 2.5, 2],
'g': [np.inf] * 3,
'h': [nan, nan, nan]
},
columns=list('abfgh'))
assert_frame_equal(df1, df2)
def test_scalar_column_with_list_slice_row_selection(self):
df1 = df[[4, 6], 2]
data = {'c': ['e', 'g']}
df2 = dx.DataFrame(data)
assert_frame_equal(df1, df2)
df1 = df[[4], 2]
data = {'c': ['e']}
df2 = dx.DataFrame(data)
assert_frame_equal(df1, df2)
df1 = df[[5, 2], 'f']
data = {'f': [4.0, 3.0]}
df2 = dx.DataFrame(data)
assert_frame_equal(df1, df2)
df1 = df[3:, 'f']
data = {'f': [3.0, 11.0, 4.0, 5.0, 1.0]}
df2 = dx.DataFrame(data)
assert_frame_equal(df1, df2)
df1 = df[5::-2, 'b']
data = {'b': [3.0, 1.0, 8.0]}
df2 = dx.DataFrame(data)
assert_frame_equal(df1, df2)
def test_add_df(self):
df_answer = dx.DataFrame({
'a':
np.array([2, 4]),
'b':
np.array([-20, 20]),
'c':
np.array([3., 16.]),
'd':
np.array([4.6, nan]),
'e':
np.array(['aa', 'bb'], dtype=object),
'f':
np.array([True, False]),
'g':
np.array([0, 172800000000000], dtype='timedelta64[ns]')
})
assert_frame_equal(self.df + self.df, df_answer)
df_answer = dx.DataFrame({
'a': array([5, 7]),
'b': array([-10, 10]),
'c': array([3.5, 10.]),
'd': array([0.3, nan])
})
df_result = self.df_number + self.df_number2
assert_frame_equal(df_result, df_answer)
def test_boolean_column_selection(self):
data = {'a': [0, 0, 5, 9, 3, 4, 5, 1],
'b': [0, 1.512344353, 8, 9, np.nan, 3, 2, 8],
'c': [''] + list('bgggzgh'),
'd': [False, False, True, False] * 2,
'e': [0, 20, 30, 4, 5, 6, 7, 8],
'f': [0., 3, 3, 3, 11, 4, 5, 1],
'g': ['', None, 'ad', 'effd', 'ef', None, 'ett', 'zzzz'],
'h': [0, 4, 5, 6, 7, 8, 9, 0],
'i': np.array([0, 7, 6, 5, 4, 3, 2, 11]),
'j': np.zeros(8, dtype='int'),
'k': np.ones(8) - 1,
'l': [np.nan] * 8}
df = dx.DataFrame(data)
df1 = df.select_dtypes('int')
df_criteria = df1[1, :] == 0
df1 = df1[:, df_criteria]
df2 = dx.DataFrame({'a': [0, 0, 5, 9, 3, 4, 5, 1],
'j': np.zeros(8, dtype='int')})
assert_frame_equal(df1, df2)
criteria = np.array([False, False, False, True, True, False,
False, False, False, False, False, False])
df1 = df[-3:, criteria]
df2 = dx.DataFrame({'d': [False, True, False],
'e': [6, 7, 8]})
assert_frame_equal(df1, df2)
def test_mod_division_frame(self):
with pytest.raises(TypeError):
self.df % 5
with pytest.raises(TypeError):
self.df.select_dtypes('str') % 10
with pytest.raises(TypeError):
self.df % 'asdf'
df = dx.DataFrame(
{
'a': [6, 7, 10],
'b': [0, 2, nan],
'f': [0, 10, 3],
'g': np.zeros(3, dtype='int'),
'h': [np.nan] * 3
},
columns=list('abfgh'))
df1 = df % 3
df2 = dx.DataFrame(
{
'a': [0, 1, 1],
'b': [0, 2, nan],
'f': [0, 1, 0],
'g': np.zeros(3, dtype='int'),
'h': [np.nan] * 3
},
columns=list('abfgh'))
assert_frame_equal(df1, df2)
def test_floordiv_frame(self):
with pytest.raises(TypeError):
self.df // 5
with pytest.raises(TypeError):
self.df.select_dtypes('str') // 10
with pytest.raises(TypeError):
self.df // 'asdf'
df = dx.DataFrame(
{
'a': [0, 0, 10],
'b': [0, 20, nan],
'f': [0, 100, 10],
'g': np.zeros(3, dtype='int'),
'h': [np.nan] * 3
},
columns=list('abfgh'))
df1 = df // 3
df2 = dx.DataFrame(
{
'a': [0, 0, 3],
'b': [0, 6, nan],
'f': [0, 33, 3],
'g': np.zeros(3, dtype='int'),
'h': [np.nan] * 3
},
columns=list('abfgh'))
assert_frame_equal(df1, df2)
def test_mult_frame(self):
df1 = self.df * 2
df2 = dx.DataFrame({
'a': [0, 0, 10],
'b': [0, 3, nan],
'c': ['', 'bb', 'gg'],
'd': [0, 0, 2],
'e': ['', None, 'adad'],
'f': [0, 8, 10],
'g': np.zeros(3, dtype='int'),
'h': [np.nan] * 3
})
assert_frame_equal(df1, df2)
df1 = 2 * self.df
df2 = dx.DataFrame({
'a': [0, 0, 10],
'b': [0, 3, nan],
'c': ['', 'bb', 'gg'],
'd': [0, 0, 2],
'e': ['', None, 'adad'],
'f': [0, 8, 10],
'g': np.zeros(3, dtype='int'),
'h': [np.nan] * 3
})
assert_frame_equal(df1, df2)
def test_greater_than_equal(self):
with pytest.raises(TypeError):
self.df >= 5
with pytest.raises(TypeError):
self.df.select_dtypes('str') >= 10
with pytest.raises(TypeError):
self.df >= 'asdf'
df = dx.DataFrame(
{
'a': [6, 7, 10],
'b': [0, 2, nan],
'f': [0, 10, 3],
'g': np.zeros(3, dtype='int'),
'h': [nan, nan, nan]
},
columns=list('abfgh'))
df1 = df >= 3
df2 = dx.DataFrame(
{
'a': [True, True, True],
'b': [False, False, False],
'f': [False, True, True],
'g': np.zeros(3, dtype='bool'),
'h': [False] * 3
},
columns=list('abfgh'))
assert_frame_equal(df1, df2)
def test_mod_bool(self):
some_bool = True
with pytest.raises(TypeError):
self.df % some_bool
with pytest.raises(TypeError):
self.df.select_dtypes('str') % some_bool
with pytest.raises(TypeError):
self.df % some_bool
df = dx.DataFrame(
{
'a': [6, 7, 10],
'b': [0, 2, nan],
'f': [0, 10, 3],
'g': np.zeros(3, dtype='int64'),
'h': [nan, nan, nan]
},
columns=list('abfgh'))
df1 = df % some_bool
df2 = dx.DataFrame(
{
'a': [0, 0, 0],
'b': [0, 0, nan],
'f': [0, 0, 0],
'g': np.zeros(3, dtype='int64'),
'h': [nan, nan, nan]
},
columns=list('abfgh'))
assert_frame_equal(df1, df2)
def test_selectdtypes_str(self):
df1 = self.df.select_dtypes('str')
df2 = dx.DataFrame(
{
'c': [''] + list('bgggzgh'),
'g': ['', None, 'ad', 'effd', 'ef', None, 'ett', 'zzzz']
},
columns=['c', 'g'])
assert_frame_equal(df1, df2)
def test_add_string(self):
df_answer = dx.DataFrame({
'a':
array(['oneone', 'twotwo'], dtype=object),
'b':
array(['threethree', 'fourfour'], dtype=object)
})
df_result = self.df_strings + self.df_strings
assert_frame_equal(df_answer, df_result)
def test_selectdtypes_float(self):
df1 = self.df.select_dtypes('float')
df2 = dx.DataFrame(
{
'b': [0, 1.512344353, 8, 9, np.nan, 3, 2, 8],
'f': [0., 3, 3, 3, 11, 4, 5, 1],
'k': np.ones(8) - 1,
'l': [np.nan] * 8
},
columns=list('bfkl'))
assert_frame_equal(df1, df2)
def test_add_one_col(self):
df_answer = dx.DataFrame({
'a': np.array([6., 4.1]),
'b': np.array([-5., 12.1]),
'c': np.array([6.5, 10.1]),
'd': np.array([7.3, nan])
})
df_result = self.df_number + self.df_one_col
assert_frame_equal(df_result, df_answer)
df_result = self.df_one_col + self.df_number
assert_frame_equal(df_result, df_answer)
def test_list_of_integer_col_selection(self):
df1 = df[:, [4, 6, 1]]
data = {'b': [1.5, 8.0, 9.0, 1.0, 2.0, 3.0, 2.0, 8.0],
'e': [10, 20, 30, 4, 5, 6, 7, 8],
'g': ['x', 'y', 'x', 'x', 'y', 'y', 'x', 'y']}
df2 = dx.DataFrame(data, columns=['e', 'g', 'b'])
assert_frame_equal(df1, df2)
df1 = df[:, [3]]
data = {'d': [True, False, True, False, True, False, True, False]}
df2 = dx.DataFrame(data)
assert_frame_equal(df1, df2)
def test_add_one_row(self):
df_answer = dx.DataFrame({
'a': array([6, 7]),
'b': array([89, 109]),
'c': array([3.6, 10.1]),
'd': array([nan, nan])
})
df_result = self.df_number + self.df_one_row_number
assert_frame_equal(df_result, df_answer)
df_result = self.df_number + self.df_one_row_number
assert_frame_equal(df_answer, df_result)
def test_list_of_string_col_selection(self):
df1 = df[:, ['b', 'd', 'a']]
data = {'a': [1, 2, 5, 9, 3, 4, 5, 1],
'b': [1.5, 8.0, 9.0, 1.0, 2.0, 3.0, 2.0, 8.0],
'd': [True, False, True, False, True, False, True, False]}
df2 = dx.DataFrame(data, columns=['b', 'd', 'a'])
assert_frame_equal(df1, df2)
df1 = df[:, ['a']]
data = {'a': [1, 2, 5, 9, 3, 4, 5, 1]}
df2 = dx.DataFrame(data)
assert_frame_equal(df1, df2)
def test_float_to_float(self):
df1 = df.astype({'e': 'float'})
df2 = dx.DataFrame({
'a': [1, nan, 10, 0],
'b': ['a', 'a', 'c', 'c'],
'c': [5, 1, nan, 3],
'd': [True, False, True, nan],
'e': [3.2, nan, 1, 0],
'f': np.array([5, 10, NaTdt, 4], 'datetime64[Y]'),
'g': np.array([22, 10, NaTtd, 8], 'timedelta64[m]')
})
assert_frame_equal(df1, df2)
def test_get_dtypes(self):
df1 = self.df.dtypes
df2 = dx.DataFrame(
{
'Column Name':
list('abcdefghijkl'),
'Data Type': [
'int', 'float', 'str', 'bool', 'int', 'float', 'str',
'int', 'int', 'int', 'float', 'float'
]
},
columns=['Column Name', 'Data Type'])
assert_frame_equal(df1, df2)
def test_slice_with_integers_col_selection(self):
df1 = df[:, 3:6]
data = {'d': [True, False, True, False, True, False, True, False],
'e': [10, 20, 30, 4, 5, 6, 7, 8],
'f': [1.0, 3.0, 3.0, 3.0, 11.0, 4.0, 5.0, 1.0]}
df2 = dx.DataFrame(data, columns=['d', 'e', 'f'])
assert_frame_equal(df1, df2)
df1 = df[:, -4::2]
data = {'e': [10, 20, 30, 4, 5, 6, 7, 8],
'g': ['x', 'y', 'x', 'x', 'y', 'y', 'x', 'y']}
df2 = dx.DataFrame(data, columns=['e', 'g'])
assert_frame_equal(df1, df2)
def test_selectdtypes_ints(self):
df1 = self.df.select_dtypes('int')
df2 = dx.DataFrame(
{
'a': [0, 0, 5, 9, 3, 4, 5, 1],
'e': [0, 20, 30, 4, 5, 6, 7, 8],
'h': [0, 4, 5, 6, 7, 8, 9, 0],
'i': np.array([0, 7, 6, 5, 4, 3, 2, 11]),
'j': np.zeros(8, dtype='int')
},
columns=list('aehij'))
assert_frame_equal(df1, df2)
def test_sort_values_one(self):
data = {'a': [4, 3, nan, 6, 3, 2],
'b': [None, 'f', 'd', 'f', 'd', 'er'],
'c': [12, 444, -5.6, 5, 1, 7]}
df = de.DataFrame(data)
df1 = df.sort_values('a')
df2 = de.DataFrame(data={'a': [2.0, 3.0, 3.0, 4.0, 6.0, nan],
'b': ['er', 'f', 'd', None, 'f', 'd'],
'c': [7.0, 444.0, 1.0, 12.0, 5.0, -5.6]})
assert_frame_equal(df1, df2)
df1 = df.sort_values('b')
df2 = de.DataFrame({'a': [nan, 3.0, 2.0, 3.0, 6.0, 4.0],
'b': ['d', 'd', 'er', 'f', 'f', None],
'c': [-5.6, 1.0, 7.0, 444.0, 5.0, 12.0]})
assert_frame_equal(df1, df2)
df = de.DataFrame({'a': [2, 3, nan, 6, 3, 2],
'b': [None, 'f', 'd', 'f', 'd', 'er'],
'c': [12, 444, -5.6, 5, 1, 7]})
df1 = df.sort_values('b', ascending=False)
df2 = de.DataFrame({'a': [3.0, 6.0, 2.0, nan, 3.0, 2.0],
'b': ['f', 'f', 'er', 'd', 'd', None],
'c': [444.0, 5.0, 7.0, -5.6, 1.0, 12.0]})
assert_frame_equal(df1, df2)
df1 = df.sort_values('a', ascending=False)
df2 = de.DataFrame({'a': [6.0, 3.0, 3.0, 2.0, 2.0, nan],
'b': ['f', 'f', 'd', None, 'er', 'd'],
'c': [5.0, 444.0, 1.0, 12.0, 7.0, -5.6]})
assert_frame_equal(df1, df2)
def test_add_string(self):
df1 = self.df.select_dtypes('str') + 'aaa'
df2 = dx.DataFrame({
'c': ['aaa', 'baaa', 'gaaa'],
'e': ['aaa', None, 'adaaa']
})
assert_frame_equal(df1, df2)
df1 = 'aaa' + self.df.select_dtypes('str')
df2 = dx.DataFrame({
'c': ['aaa', 'aaab', 'aaag'],
'e': ['aaa', None, 'aaaad']
})
assert_frame_equal(df1, df2)
def test_where_string_cols(self):
data = {'a': [9, 10, 9, 9, 10],
'b': [0, nan, nan, 0, 1],
'c': [''] + list('eeaz'),
'd': [False, False, True, False, True],
'e': [0, 20, 30, 4, 4],
'f': ['a', nan, 'ad', None, 'ad'],
'g': [np.nan] * 5}
df = de.DataFrame(data)
cond = df[:, 'e'] > 9
df1 = df[:, ['c', 'f']].where(cond)
df2 = de.DataFrame({'c': [None, 'e', 'e', None, None],
'f': [None, None, 'ad', None, None]})
assert_frame_equal(df1, df2)
df1 = df[:, ['c', 'f']].where(cond, 22, 99)
df2 = de.DataFrame({'c': [99, 22, 22, 99, 99], 'f': [99, 22, 22, 99, 99]})
assert_frame_equal(df1, df2)
df1 = df[:, ['c', 'f']].where(cond, 't')
df2 = de.DataFrame({'c': [None, 't', 't', None, None], 'f': [None, 't', 't', None, None]})
assert_frame_equal(df1, df2)
df1 = df[:, ['c', 'f']].where(cond, 't', 'y')
df2 = de.DataFrame({'c': ['y', 't', 't', 'y', 'y'], 'f': ['y', 't', 't', 'y', 'y']})
assert_frame_equal(df1, df2)