Metadata API

Metadata classes define the structure of data assets and columns.

AssetMetadata

class wxdi.dq_validator.metadata.AssetMetadata(table_name: str, columns: List[ColumnMetadata])

Bases: object

Metadata for a data asset (table)

Initialize asset metadata

Parameters:

• table_name (str) – Name of the table/asset

• columns (List[ColumnMetadata]) – List of column metadata in order

Raises:

ValueError – If columns list is empty or contains duplicate names

get_column_index(column_name: str)

Get array index for a column name

Parameters:

column_name (str) – Name of the column

Return type:

int

Returns:

Index of the column in the record array

Raises:

ValueError – If column name not found

get_column(column_name: str)

Get column metadata by name

Parameters:

column_name (str) – Name of the column

Return type:

ColumnMetadata

Returns:

ColumnMetadata object

Raises:

ValueError – If column name not found

get_value(record: List[Any], column_name: str)

Extract value from record array by column name

Parameters:

• record (List[Any]) – The record array

• column_name (str) – Name of the column

Return type:

Any

Returns:

Value at the column’s position

Raises:

ValueError – If column not found or record too short

ColumnMetadata

class wxdi.dq_validator.metadata.ColumnMetadata(name: str, data_type: DataType, length: int | None = None, scale: int | None = None, precision: int | None = None, nullable: bool = True)

Bases: object

Metadata for a single column

Initialize column metadata

Parameters:

• name (str) – Column name

• data_type (DataType) – Data type from DataType enum

• length (int | None, default: None) – Maximum length (for strings)

• scale (int | None, default: None) – Number of digits after decimal (for decimals)

• precision (int | None, default: None) – Total number of digits (for decimals)

• nullable (bool, default: True) – Whether column can be null

DataType

class wxdi.dq_validator.datatypes.DataType(dtype: str | None = DataTypeEnum.UNKNOWN, length: int | None = 0, precision: int | None = 0, scale: int | None = 0)

Bases: object

Parameters:

• dtype (str | None)

• length (int | None)

• precision (int | None)

• scale (int | None)

is_integer()

is_compatible(inferred: DataType)

IBM DataType.isCompatibleWithValue

Return type:

bool

Parameters:

inferred (DataType)

DataTypeEnum

class wxdi.dq_validator.datatypes.DataTypeEnum(*values)

Bases: str, Enum

INT8 = 'INT8'

INT16 = 'INT16'

INT32 = 'INT32'

INT64 = 'INT64'

DECIMAL = 'DECIMAL'

STRING = 'STRING'

DATE = 'DATE'

TIME = 'TIME'

TIMESTAMP = 'TIMESTAMP'

UNKNOWN = 'UNKNOWN'

Usage Examples

See Core Concepts for detailed usage examples.