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HOCON Format (Human-Optimized Config Object Notation)

Description​

HOCON (Human-Optimized Config Object Notation) is a configuration file format developed by Lightbend (formerly Typesafe) for use with their products like Play Framework and Akka. It's a superset of JSON and is designed to be more human-friendly.

File Extensions​

  • .hocon - HOCON configuration files

Implementation Details​

Reading​

The HOCON implementation:

  • Uses pyhocon library for parsing
  • Parses HOCON configuration files
  • Converts HOCON structures to Python dictionaries
  • Handles arrays and nested objects
  • Groups configuration by keys

Writing​

Writing is not currently supported for HOCON format.

Key Features​

  • Human-friendly: More readable than JSON
  • JSON superset: Extends JSON with additional features
  • Configuration format: Designed for configuration files
  • Nested data: Supports complex nested structures

Usage​

from iterable import open_iterable

# Basic reading
source = open_iterable('config.hocon')
for row in source:
    print(row)  # Configuration entries
source.close()

Parameters​

  • encoding (str): File encoding (default: utf8)

Limitations​

  1. Read-only: HOCON format does not support writing
  2. pyhocon dependency: Requires pyhocon package
  3. Configuration focus: Designed for configuration, not general data
  4. Memory usage: Entire file is loaded into memory

Compression Support​

HOCON files can be compressed with all supported codecs:

  • GZip (.hocon.gz)
  • BZip2 (.hocon.bz2)
  • LZMA (.hocon.xz)
  • LZ4 (.hocon.lz4)
  • ZIP (.hocon.zip)
  • Brotli (.hocon.br)
  • ZStandard (.hocon.zst)

Use Cases​

  • Play Framework: Configuration for Play applications
  • Akka: Configuration for Akka systems
  • Configuration files: Human-friendly configuration
  • Lightbend products: Products from Lightbend/Typesafe
  • JSON - Base format that HOCON extends
  • YAML - Another configuration format
  • TOML - Another configuration format