def test_transform_model_enabled_reject_sampling_error(self):
"""Test that the ``Constraint.transform`` method raises an error appropriately.
If the column model is used but doesn't return valid rows,
reject sampling should be used to get the valid rows. If it doesn't
get any valid rows in 100 tries, a ``ValueError`` is raised.
Setup:
- The ``_columns_model`` is fixed to always return an empty ``DataFrame``.
Input:
- Table with some missing columns.
Side Effect:
- ``ValueError`` raised.
"""
# Setup
instance = Constraint(handling_strategy='transform')
instance.constraint_columns = ('a', 'b')
instance._hyper_transformer = Mock()
instance._columns_model = Mock()
transformed_conditions = pd.DataFrame([[1]], columns=['b'])
instance._columns_model.sample.return_value = pd.DataFrame()
instance._hyper_transformer.transform.return_value = transformed_conditions
instance._hyper_transformer.reverse_transform.return_value = pd.DataFrame(
)
# Run / Assert
data = pd.DataFrame([[1, 2], [3, 4]], columns=['b', 'c'])
with pytest.raises(ValueError):
instance.transform(data)
def test_transform_model_enabled_some_columns_missing(self):
"""Test that the ``Constraint.transform`` method uses column model.
If ``table_data`` is missing some of the ``constraint_columns``,
the ``_column_model`` should be used to sample the rest and the
data should be transformed.
Input:
- Table with some missing columns.
Output:
- Transformed data with all columns.
"""
# Setup
instance = Constraint(handling_strategy='transform')
instance._transform = lambda x: x
instance.constraint_columns = ('a', 'b')
instance._hyper_transformer = Mock()
instance._columns_model = Mock()
conditions = [
pd.DataFrame([[5, 1, 2]], columns=['a', 'b', 'c']),
pd.DataFrame([[6, 3, 4]], columns=['a', 'b', 'c'])
]
transformed_conditions = [
pd.DataFrame([[1]], columns=['b']),
pd.DataFrame([[3]], columns=['b'])
]
instance._columns_model.sample.return_value = pd.DataFrame(
[[1, 2, 3]], columns=['b', 'c', 'a'])
instance._hyper_transformer.transform.side_effect = transformed_conditions
instance._hyper_transformer.reverse_transform.side_effect = conditions
# Run
data = pd.DataFrame([[1, 2], [3, 4]], columns=['b', 'c'])
transformed_data = instance.transform(data)
# Assert
expected_tranformed_data = pd.DataFrame([[1, 2, 3]],
columns=['b', 'c', 'a'])
expected_result = pd.DataFrame([[5, 1, 2], [6, 3, 4]],
columns=['a', 'b', 'c'])
model_calls = instance._columns_model.sample.mock_calls
assert len(model_calls) == 2
instance._columns_model.sample.assert_any_call(num_rows=1,
conditions={'b': 1})
instance._columns_model.sample.assert_any_call(num_rows=1,
conditions={'b': 3})
reverse_transform_calls = instance._hyper_transformer.reverse_transform.mock_calls
pd.testing.assert_frame_equal(reverse_transform_calls[0][1][0],
expected_tranformed_data)
pd.testing.assert_frame_equal(reverse_transform_calls[1][1][0],
expected_tranformed_data)
pd.testing.assert_frame_equal(transformed_data, expected_result)
def test_transform_model_enabled_reject_sampling_duplicates_valid_rows(
self):
"""Test the ``Constraint.transform`` method's reject sampling fall back.
If the column model is used but doesn't return valid rows,
reject sampling should be used to get the valid rows. If after 100
tries, some valid rows are created but not enough, then the valid rows
are duplicated to meet the ``num_rows`` requirement.
Setup:
- The ``_columns_model`` returns some valid rows the first time, and then
an empy ``DataFrame`` for every other call.
Input:
- Table with some missing columns.
Output:
- Transformed data with all columns.
"""
# Setup
instance = Constraint(handling_strategy='transform')
instance._transform = lambda x: x
instance.constraint_columns = ('a', 'b')
instance._hyper_transformer = Mock()
instance._columns_model = Mock()
transformed_conditions = [
pd.DataFrame([[1], [1], [1], [1], [1]], columns=['b'])
]
instance._columns_model.sample.side_effect = [
pd.DataFrame([[1, 2], [1, 3]], columns=['a', 'b'])
] + [pd.DataFrame()] * 100
instance._hyper_transformer.transform.side_effect = transformed_conditions
instance._hyper_transformer.reverse_transform = lambda x: x
# Run
data = pd.DataFrame([[1], [1], [1], [1], [1]], columns=['b'])
transformed_data = instance.transform(data)
# Assert
expected_result = pd.DataFrame(
[[1, 2], [1, 3], [1, 2], [1, 3], [1, 2]], columns=['a', 'b'])
model_calls = instance._columns_model.sample.mock_calls
assert len(model_calls) == 101
instance._columns_model.sample.assert_any_call(num_rows=5,
conditions={'b': 1})
pd.testing.assert_frame_equal(transformed_data, expected_result)
def test_transform_model_enabled_reject_sampling(self):
"""Test the ``Constraint.transform`` method's reject sampling.
If the column model is used but doesn't return valid rows,
reject sampling should be used to get the valid rows.
Setup:
- The ``_columns_model`` returns some valid_rows the first time,
and then the rest with the next call.
Input:
- Table with some missing columns.
Output:
- Transformed data with all columns.
"""
# Setup
instance = Constraint(handling_strategy='transform')
instance._transform = lambda x: x
instance.constraint_columns = ('a', 'b')
instance._hyper_transformer = Mock()
instance._columns_model = Mock()
transformed_conditions = [
pd.DataFrame([[1], [1], [1], [1], [1]], columns=['b'])
]
instance._columns_model.sample.side_effect = [
pd.DataFrame([[1, 2], [1, 3]], columns=['a', 'b']),
pd.DataFrame([[1, 4], [1, 5], [1, 6], [1, 7]], columns=['a', 'b']),
]
instance._hyper_transformer.transform.side_effect = transformed_conditions
instance._hyper_transformer.reverse_transform = lambda x: x
# Run
data = pd.DataFrame([[1], [1], [1], [1], [1]], columns=['b'])
transformed_data = instance.transform(data)
# Assert
expected_result = pd.DataFrame(
[[1, 2], [1, 3], [1, 4], [1, 5], [1, 6]], columns=['a', 'b'])
model_calls = instance._columns_model.sample.mock_calls
assert len(model_calls) == 2
instance._columns_model.sample.assert_any_call(num_rows=5,
conditions={'b': 1})
assert model_calls[1][2]['num_rows'] > 3
pd.testing.assert_frame_equal(transformed_data, expected_result)