tlc.core.operations.operation

Abstract base class for operations and its specialized subclasses.

The Operation class serves as an abstract base class for different types of operations that can be applied to tables.

• Operation: Abstract base class for table operations.

• LocalOperation: Specialized class for operations acting on individual rows.

• GlobalOperation: Specialized class for operations acting on entire columns.

Module Contents

Classes

Class	Description
CalculateSchemaContext	Represents the context in which a schema is calculated.
CalculateValueContext	Represents the context in which a value is calculated.
GlobalOperation	An abstract base class representing a global operation on data.
LocalOperation	An abstract base class representing a local operation on data.
Operation	An abstract base class representing a generic operation on data.

API

class CalculateSchemaContext(

input_table_row_schemas: dict[str, Schema],

)

Represents the context in which a schema is calculated.

class CalculateValueContext(

table: Table,

input_table_schemas: dict[str, Schema],

)

Represents the context in which a value is calculated.

class GlobalOperation

Bases: tlc.core.operations.operation.Operation

An abstract base class representing a global operation on data.

Acts on entire columns of data.

class LocalOperation

Bases: tlc.core.operations.operation.Operation

An abstract base class representing a local operation on data.

Subclasses must implement the calculate_single_value method.

abstract calculate_single_value(

row: Mapping[str, object],

calculate_value_context: CalculateValueContext,

) → object

Calculate a single value for a row based on the operation.

populate_column_data(

calculate_value_context: CalculateValueContext,

) → list[object]

Populate a list of values for a new column in the table.

class Operation

Bases: abc.ABC

An abstract base class representing a generic operation on data.

Subclasses must implement the calculate_schema as well as either populate_column_data for global operations or calculate_single_value for local operations.

abstract calculate_schema(

calculate_schema_context: CalculateSchemaContext,

) → Schema

Calculate the schema for the resulting table based on input schemas.

column_name() → str

Generate a unique column name based on the object id.

abstract populate_column_data(

calculate_value_context: CalculateValueContext,

) → list[Any]

Populate column data based on the operation and input table.