Preprocessors

TabularPreproc

from_schema classmethod

from_schema(
    schema: Schema,
    ctx_cols: dict[str, Sequence[str]] | None = None,
    preprocessors: dict[
        str, dict[str, ColumnPreproc | ArColumn | None]
    ]
    | None = None,
) -> TabularPreproc

Build a preprocessor for tabular data from the Schema.

Parameters:

Name	Type	Description	Default
schema	Schema	A Schema object.	required
ctx_cols	dict[str, Sequence[str]] | None	A dictionary with the columns to be used as context. May contain: 1. Only the root table as key and a subset of its columns as value. 2. All the tables as keys and a subset of each table's columns as values.	None
preprocessors	dict[str, dict[str, ColumnPreproc | ArColumn | None]] | None	A dictionary containing preprocessing instructions for each column in the schema. Keys are table names, values are dictionaries with column names as keys and preprocessing instructions as values. Preprocessing instructions can be instances of ColumnPreproc, a column preprocessor, or None. If None the default preprocessor will be instantiated based on the Column type defined in the Schema.	None

Returns:

Type	Description
TabularPreproc	A TabularPreproc object.

fit

fit(data: RelationalData) -> TabularPreproc

Fit the preprocessor to the given RelationalData.

Parameters:

Name	Type	Description	Default
data	RelationalData	The RelationalData to fit the preprocessor to.	required

Returns:

Type	Description
TabularPreproc	The fitted TabularPreproc object.

TextPreproc

from_schema_table classmethod

from_schema_table(
    schema: Schema, table: str
) -> TextPreproc

Build a preprocessor for the text columns of a table from the Schema.

Parameters:

Name	Type	Description	Default
schema	Schema	A Schema object.	required
table	str	Name of the target table in the schema that contains text columns.	required

Returns:

Type	Description
TextPreproc	A TextPreproc object.

from_tabular classmethod

from_tabular(
    preproc: TabularPreproc[_AP], table: str
) -> TextPreproc

Build a preprocessor for the text columns of a table from the TabularPreproc used for the tabular data.

Parameters:

Name	Type	Description	Default
preproc	TabularPreproc[_AP]	A TabularPreproc object used for the tabular part of the data.	required
table	str	Name of the target table in the schema that contains text columns.	required

Returns:

Type	Description
TextPreproc	A TextPreproc object.

fit

fit(data: RelationalData) -> TextPreproc

Fit the preprocessor to the given RelationalData.

Parameters:

Name	Type	Description	Default
data	RelationalData	The RelationalData to fit the preprocessor to.	required

Returns:

Type	Description
TextPreproc	The fitted TextPreproc object.

ColumnPreproc dataclass

Preprocessing instructions for a column.

Parameters:

Name	Type	Description	Default
special_values	Sequence | None	A sequence of special values to handle during preprocessing.	None
impute_nan	bool | None	A flag indicating whether to impute NaN values during preprocessing. If True, NaN values will not be sampled during the generation of synthetic data.	None
non_sample_values	Sequence | None	A sequence of values that should not be sampled during the generation of synthetic data.	None
protection	Protection | bool | None	A Protection object or boolean flag indicating whether to apply protection to the column. If boolean, the default protection is applied, otherwise the Protection object configures the protection.	None