README.md

bencoder

A simple up-to-date bencode decoder-encoder library on pure Python.

I wrote this simple implementation because of the lack of bencoding libraries compatible with Python 3.

Bencode (pronounced like B encode) is the encoding used by the peer-to-peer file sharing system BitTorrent for storing and transmitting loosely structured data.

Installation

You can install the package directly from PyPI using pip.

pip install bencoder

Or you can use this source

git clone git@github.com:utdemir/bencoder.git
cd bencoder 
python setup.py install

Usage

>>> import bencoder

>>> print(bencoder.decode.__doc__)

    Decodes given bencoded bytes object.

    >>> decode(b'i-42e')
    -42
    >>> decode(b'4:utku') == b'utku'
    True
    >>> decode(b'li1eli2eli3eeee')
    [1, [2, [3]]]
    >>> decode(b'd3:bar4:spam3:fooi42ee') == {b'bar': b'spam', b'foo': 42}
    True
    
>>> print(bencoder.encode.__doc__)

    bencodes given object. Given object should be a int,
    bytes, list or dict.

    >>> [encode(i) for i in (-2, 42, b"answer", b"")]             
               == [b'i-2e', b'i42e', b'6:answer', b'0:']
    True
    >>> encode([b'a', 42, [13, 14]]) == b'l1:ai42eli13ei14eee'
    True
    >>> encode({b'bar': b'spam', b'foo': 42, b'mess': [1, b'c']}) \
               == b'd3:bar4:spam3:fooi42e4:messli1e1:cee'
    True

Real Life Scenario

>>> import bencoder
>>> f = open("archlinux-2014.05.01-dual.iso.torrent", "rb")
>>> d = bencoder.decode(f.read())
>>> del d[b"info"][b"pieces"] # That's a long hash
>>> from pprint import pprint
>>> pprint(d)
{b'announce': b'http://tracker.archlinux.org:6969/announce',
b'comment': b'Arch Linux 2014.05.01 (www.archlinux.org)',
b'created by': b'mktorrent 1.0',
b'creation date': 1398921725,
b'info': {b'length': 565182464,
        b'name': b'archlinux-2014.05.01-dual.iso',
        b'piece length': 524288},
b'url-list': [b'http://mirror.aarnet.edu.au/pub/archlinux/iso/2014.05.01/',
            b'http://ftp.iinet.net.au/pub/archlinux/iso/2014.05.01/',
            ....
            b'http://mirror-fpt-telecom.fpt.net/archlinux/iso/2014.05.01/']}