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EDN Format (Extensible Data Notation)

Description​

EDN (Extensible Data Notation) is a data format used in Clojure. It's similar to JSON but supports more data types and is extensible. EDN is a subset of Clojure's literal syntax and is used for data interchange in Clojure applications.

File Extensions​

  • .edn - EDN format files

Implementation Details​

Reading​

The EDN implementation:

  • Uses edn_format or pyedn library for parsing
  • Parses EDN data structures
  • Supports multiple EDN values (line-delimited)
  • Converts EDN data to Python objects

Writing​

Writing support:

  • Encodes Python objects to EDN format
  • Writes EDN data
  • Supports nested structures

Key Features​

  • Clojure format: Used in Clojure applications
  • Extensible: Supports custom types
  • Nested data: Supports complex nested structures
  • Type preservation: Maintains data types

Usage​

from iterable import open_iterable

# Basic reading
with open_iterable('data.edn') as source:
    for row in source:
        print(row)

# Writing
with open_iterable('output.edn', mode='w') as dest:
    dest.write({'name': 'John', 'age': 30})

Parameters​

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

Limitations​

  1. Dependency: Requires edn_format or pyedn package
  2. Clojure-specific: Primarily used in Clojure ecosystem
  3. Less common: Not as widely used as JSON
  4. Memory usage: Entire file may be loaded into memory

Compression Support​

EDN files can be compressed with all supported codecs:

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

Use Cases​

  • Clojure applications: Data interchange in Clojure
  • Configuration: Clojure-style configuration files
  • Data exchange: Clojure-to-Python data exchange

Error Handling​

  • Missing dependency: optional libraries raise ImportError with an install hint (pip install 'iterabledata[<extra>]' when an extra exists).
  • Write mode: read-only formats raise WriteNotSupportedError or ValueError when opened with mode="w".
  • Bad or unsupported input: may raise ValueError, OSError, or library-specific errors.
  • See Troubleshooting for decoding, detection, and engine issues.
  • JSON - Similar structure
  • YAML - Another configuration format