def test_nonexistent_columns_explicit_fail(simple_dataframe): """ If a nonexistent column is selected, KeyError is raised. """ mapper = DataFrameMapper(None) with pytest.raises(KeyError): mapper._get_col_subset(simple_dataframe, ["nonexistent_feature"])
def test_get_col_subset_single_column_array(simple_dataframe): """ Selecting a single column should return a 1-dimensional numpy array. """ mapper = DataFrameMapper(None) array = mapper._get_col_subset(simple_dataframe, "a") assert type(array) == np.ndarray assert array.shape == (len(simple_dataframe["a"]),)
def test_get_col_subset_single_column_array(simple_dataframe): """ Selecting a single column should return a 1-dimensional numpy array. """ mapper = DataFrameMapper(None) array = mapper._get_col_subset(simple_dataframe, "a") assert type(array) == np.ndarray assert array.shape == (len(simple_dataframe["a"]),)
def test_get_col_subset_single_column_list(simple_dataframe): """ Selecting a list of columns (even if the list contains a single element) should return a 2-dimensional numpy array. """ mapper = DataFrameMapper(None) array = mapper._get_col_subset(simple_dataframe, ["a"]) assert type(array) == np.ndarray assert array.shape == (len(simple_dataframe["a"]), 1)
def test_get_col_subset_single_column_list(simple_dataframe): """ Selecting a list of columns (even if the list contains a single element) should return a 2-dimensional numpy array. """ mapper = DataFrameMapper(None) array = mapper._get_col_subset(simple_dataframe, ["a"]) assert type(array) == np.ndarray assert array.shape == (len(simple_dataframe["a"]), 1)