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SMILE Format

Description​

SMILE (Smile is a Machine-Interchangeable Language for Everything) is a binary data format similar to JSON but more compact. It was developed by the Jackson JSON library team and provides efficient binary serialization of JSON-like data structures.

File Extensions​

  • .smile - SMILE format files

Implementation Details​

Reading​

The SMILE implementation:

  • Imports smile when installed (there is no PyPI extra; see Limitations)
  • Reads binary SMILE data
  • Supports single documents or arrays
  • Converts SMILE data to Python objects

Writing​

Writing support:

  • Encodes Python objects to SMILE format
  • Writes binary SMILE data
  • Supports nested structures

Key Features​

  • Binary format: More compact than JSON
  • JSON-compatible: Same data structures as JSON
  • Nested data: Supports complex nested structures
  • Type preservation: Maintains data types

Usage​

from iterable import open_iterable

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

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

Parameters​

No specific parameters required.

Limitations​

  1. Not on PyPI: There is no iterabledata extra for SMILE. The reader imports smile and the ImportError names smile-json, which is not a pip-installable package today.
  2. Binary format: Not human-readable
  3. Memory usage: Entire file may be loaded into memory
  4. Less common: Not as widely used as JSON or MessagePack

Compression Support​

SMILE files can be compressed with all supported codecs:

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

Use Cases​

  • Binary JSON: When JSON is too verbose
  • Data storage: Efficient binary storage
  • Jackson integration: Working with Jackson-based systems

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.