pyarrow.dataset.HivePartitioning

class pyarrow.dataset.HivePartitioning

Bases: pyarrow._dataset.Partitioning

A Partitioning for “/$key=$value/” nested directories as found in Apache Hive.

Multi-level, directory based partitioning scheme originating from Apache Hive with all data files stored in the leaf directories. Data is partitioned by static values of a particular column in the schema. Partition keys are represented in the form $key=$value in directory names. Field order is ignored, as are missing or unrecognized field names.

For example, given schema<year:int16, month:int8, day:int8>, a possible path would be “/year=2009/month=11/day=15”.

Parameters

• schema (Schema) – The schema that describes the partitions present in the file path.

• dictionaries (Dict[str, Array]) – If the type of any field of schema is a dictionary type, the corresponding entry of dictionaries must be an array containing every value which may be taken by the corresponding column or an error will be raised in parsing.

Returns

HivePartitioning

Examples

>>> from pyarrow.dataset import HivePartitioning
>>> partitioning = HivePartitioning(
...     pa.schema([("year", pa.int16()), ("month", pa.int8())]))
>>> print(partitioning.parse("/year=2009/month=11"))
((year == 2009:int16) and (month == 11:int8))

__init__(*args, **kwargs)

Initialize self. See help(type(self)) for accurate signature.

Methods

__init__(*args, **kwargs)	Initialize self.
discover	Discover a HivePartitioning.
parse

Attributes

schema

The arrow Schema attached to the partitioning.

static discover()

Discover a HivePartitioning.

Parameters

• infer_dictionary (bool, default False) – When inferring a schema for partition fields, yield dictionary encoded types instead of plain. This can be more efficient when materializing virtual columns, and Expressions parsed by the finished Partitioning will include dictionaries of all unique inspected values for each field.

• max_partition_dictionary_size (int, default 0) – Synonymous with infer_dictionary for backwards compatibility with 1.0: setting this to -1 or None is equivalent to passing infer_dictionary=True.

Returns

PartitioningFactory – To be used in the FileSystemFactoryOptions.

parse()

schema

The arrow Schema attached to the partitioning.