_transformation_utils

Useful functions to be used with transformations.

Functions

generate_nested_transformation()	Generate a nested transformation.
rename_table()	Renames tables.
delete_table()	Deletes tables.
persist_table()	Persists tables.
unpersist_table()	Unpersists tables.
get_table_from_ref()	Returns a GetValue transformation finding the table specified.

generate_nested_transformation(base_transformation, parent_reference, generator_dict, table_identifier=None)

Generate a nested transformation.

At a high level, this function chooses an appropriate transformation by keying into the generator dictionary at the parent_reference’s Metric, then applies the selected transformation at parent_reference in the output of base_transformation.

Parameters

• base_transformation (tmlt.core.transformations.base.Transformation) – Transformation to be used as a starting point.

• parent_reference (tmlt.analytics._table_reference.TableReference) – The parent TableReference of base_transformation’s associated TableReference.

• generator_dict (Dict[Type[tmlt.core.metrics.Metric], Callable[[tmlt.core.domains.base.Domain, tmlt.core.metrics.Metric, tmlt.analytics._table_identifier.Identifier], tmlt.core.transformations.base.Transformation]]) – a dictionary of the form { Metric : generator() }, where generator() is a function which takes the associated domain and metric of the parent_reference and generates a transformation using the Metric, e.g. generator(parent_domain, parent_metric, target_identifier)

• table_identifier (Optional[tmlt.analytics._table_identifier.Identifier]) – identifier for new table in case of rename and original table in case of delete/persist/unpersist

Return type

Tuple[tmlt.core.transformations.base.Transformation, tmlt.analytics._table_reference.TableReference]

rename_table(base_transformation, base_ref, new_table_id)

Renames tables.

A single value is transformed and added to the dictionary at a new key. Note that the original value is left unchanged in the dictionary.

Parameters

• base_transformation (tmlt.core.transformations.base.Transformation) –

• base_ref (tmlt.analytics._table_reference.TableReference) –

• new_table_id (tmlt.analytics._table_identifier.Identifier) –

Return type

Tuple[tmlt.core.transformations.base.Transformation, tmlt.analytics._table_reference.TableReference]

delete_table(base_transformation, base_ref)

Deletes tables.

Parameters

• base_transformation (tmlt.core.transformations.base.Transformation) –

• base_ref (tmlt.analytics._table_reference.TableReference) –

Return type

tmlt.core.transformations.base.Transformation

persist_table(base_transformation, base_ref, new_table_id=None)

Persists tables.

Parameters

• base_transformation (tmlt.core.transformations.base.Transformation) –

• base_ref (tmlt.analytics._table_reference.TableReference) –

• new_table_id (Optional[tmlt.analytics._table_identifier.Identifier]) –

Return type

Tuple[tmlt.core.transformations.base.Transformation, tmlt.analytics._table_reference.TableReference]

unpersist_table(base_transformation, base_ref)

Unpersists tables.

Parameters

• base_transformation (tmlt.core.transformations.base.Transformation) –

• base_ref (tmlt.analytics._table_reference.TableReference) –

Return type

tmlt.core.transformations.base.Transformation

get_table_from_ref(transformation, ref)

Returns a GetValue transformation finding the table specified.

Parameters

• transformation (tmlt.core.transformations.base.Transformation) –

• ref (tmlt.analytics._table_reference.TableReference) –

Return type

tmlt.core.transformations.base.Transformation