Implementation:Unstructured IO Unstructured PartitionStrategy

Knowledge Sources	Unstructured
Domains	Document_Processing, Configuration
Last Updated	2026-02-12 00:00 GMT

Overview

Concrete tool for selecting document partitioning strategies provided by the Unstructured library.

Description

The PartitionStrategy class defines string constants for the four supported partitioning strategies: AUTO, FAST, HI_RES, and OCR_ONLY. These constants are used as the strategy parameter throughout the partition pipeline to control extraction behavior.

Usage

Import this class when you need to specify a partitioning strategy programmatically rather than using raw strings. Using the constants ensures consistency and enables IDE autocompletion.

Code Reference

Source Location

• Repository: unstructured
• File: unstructured/partition/utils/constants.py
• Lines: 17-21

Signature

class PartitionStrategy:
    AUTO = "auto"
    FAST = "fast"
    OCR_ONLY = "ocr_only"
    HI_RES = "hi_res"

Import

from unstructured.partition.utils.constants import PartitionStrategy

I/O Contract

Inputs

Name	Type	Required	Description
(none)			Class attributes are string constants, no instantiation needed

Outputs

Name	Type	Description
AUTO	str	"auto" - automatically selects strategy per page
FAST	str	"fast" - text extraction only (no layout detection)
OCR_ONLY	str	"ocr_only" - OCR-based extraction for scanned documents
HI_RES	str	"hi_res" - layout detection with computer vision models

Usage Examples

Using Strategy Constants

from unstructured.partition.auto import partition
from unstructured.partition.utils.constants import PartitionStrategy

# Use high-resolution mode for accurate layout detection
elements = partition(
    filename="report.pdf",
    strategy=PartitionStrategy.HI_RES,
)

# Use fast mode for quick text extraction
elements = partition(
    filename="article.pdf",
    strategy=PartitionStrategy.FAST,
)

Related Pages

Implements Principle

• Principle:Unstructured_IO_Unstructured_Strategy_Selection

Uses Heuristic

• Heuristic:Unstructured_IO_Unstructured_Strategy_Fallback_Chain