class bach.SeriesDict

(engine, base_node, index, name, expression, group_by, instance_dtype, order_by=None, **kwargs)


A Series that represents a dictionary-like type and its specific operations. On BigQuery this is backed by the STRUCT data type. On other databases this type is not supported.

instance_dtype: An instance of this class expects an instance_dtype that’s a dictionary. With each key being the name of a field, and the value being an instance-dtype describing that field. The values represented by such a Series must then be dictionaries with the exact same field names as the instance-dtype, and the specified data types for the fields.

Example - BigQuery db_dtype: 'STRUCT<a INT64, b ARRAY[FLOAT64], c <STRUCT x BOOL, y: INT64>>' instance_dtype: {'a': 'int64', b: ['float64'], 'c': {'x': 'bool', 'y': 'int64'}

Database support and types

  • Postgres: not supported. Use SeriesJson for similar functionality.
  • BigQuery: utilizes the ‘STRUCT’ database type.