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FlexBuffers Format

Description​

FlexBuffers is a schemaless binary serialization format developed by Google as part of FlatBuffers. Unlike FlatBuffers, FlexBuffers doesn't require a schema and is more flexible. It's designed for cases where you need a flexible, schemaless binary format.

File Extensions​

  • .flexbuf - FlexBuffers files
  • .flexbuffers - FlexBuffers files (alias)

Implementation Details​

Reading​

The FlexBuffers implementation:

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

Writing​

Writing support:

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

Key Features​

  • Schemaless: No schema required
  • Binary format: Efficient binary serialization
  • Flexible: More flexible than FlatBuffers
  • Nested data: Supports complex nested structures
  • Type preservation: Maintains data types

Usage​

from iterable import open_iterable

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

# Writing
with open_iterable('output.flexbuf', 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 FlexBuffers. The reader imports flexbuffers, 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 other formats

Compression Support​

FlexBuffers files can be compressed with all supported codecs:

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

Use Cases​

  • Schemaless binary: When you need schemaless binary format
  • Flexible serialization: Dynamic data structures
  • Game development: Game data serialization

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.