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Bencode Format

Description​

Bencode (pronounced "B-encode") is the encoding format used by the BitTorrent protocol. It's a simple format for encoding data structures (strings, integers, lists, and dictionaries) in a compact binary format. Bencode is commonly used in .torrent files.

File Extensions​

  • .torrent - BitTorrent files (uses Bencode)

Implementation Details​

Reading​

The Bencode implementation:

  • Uses bencode or bencodepy library for decoding
  • Parses Bencode-encoded data
  • Handles torrent file structures
  • Converts Bencode data to Python objects

Writing​

Writing support:

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

Key Features​

  • BitTorrent format: Used by BitTorrent protocol
  • Simple encoding: Compact binary format
  • Nested data: Supports lists and dictionaries
  • Type preservation: Maintains data types

Usage​

from iterable import open_iterable

# Basic reading
with open_iterable('file.torrent') as source:
    for row in source:
        print(row)  # Contains torrent metadata

# Writing
with open_iterable('output.torrent', mode='w') as dest:
    dest.write({'info': {...}, 'announce': 'http://...'})

Parameters​

No specific parameters required.

Limitations​

  1. Dependency: Requires bencode or bencodepy package
  2. Binary format: Not human-readable
  3. BitTorrent-specific: Primarily used for BitTorrent files
  4. Memory usage: Entire file may be loaded into memory

Compression Support​

Bencode files can be compressed with all supported codecs:

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

Note: Torrent files are typically not compressed.

Use Cases​

  • BitTorrent: Working with .torrent files
  • P2P protocols: Peer-to-peer protocol data
  • File sharing: BitTorrent file sharing

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.