libtorrent python binding

Author:	Arvid Norberg, arvid@rasterbar.com

Table of contents

building
- building using setup.py
- building using boost build
using libtorrent in python

building

Building the libtorrent python bindings will produce a shared library (DLL) which is a python module that can be imported in a python program.

building using setup.py

There is a setup.py shipped with libtorrent that can be used on windows. On windows the setup.py will invoke bjam and assume that you have boost sources at $BOOST_PATH. The resulting executable is self-contained, it does not depend any boost or libtorrent dlls.

On other systems, the setup.py is generated by running ./configure --enable-python-binding.

To build the Python bindings do:

Run:
```
python setup.py build
```
As root, run:
```
python setup.py install
```

building using boost build

To set up your build environment, you need to add some settings to your $BOOST_BUILD_PATH/user-config.jam.

Make sure your user config contains the following line:

using python : 2.3 ;

Set the version to the version of python you have installed or want to use. If you've installed python in a non-standard location, you have to add the prefix path used when you installed python as a second option. Like this:

using python : 2.6 : /usr/bin/python2.6 : /usr/include/python2.6 : /usr/lib/python2.6 ;

The bindings require at least python version 2.2.

For more information on how to install and set up boost-build, see the building libtorrent section.

Once you have boost-build set up, you cd to the bindings/python directory and invoke bjam with the apropriate settings. For the available build variants, see libtorrent build options.

For example:

$ bjam dht-support=on boost=source release link=static

On Mac OS X, this will produce the following python module:

bin/darwin-4.0/release/dht-support-on/link-static/logging-none/threading-multi/libtorrent.so

using libtorrent in python

The python interface is nearly identical to the C++ interface. Please refer to the library reference. The main differences are:

asio::tcp::endpoint: The endpoint type is represented as a tuple of a string (as the address) and an int for the port number. E.g. ('127.0.0.1', 6881) represents the localhost port 6881.
libtorrent::time_duration: The time duration is represented as a number of seconds in a regular integer.

The following functions takes a reference to a container that is filled with entries by the function. The python equivalent of these functions instead returns a list of entries.

torrent_handle::get_peer_info
torrent_handle::file_progress
torrent_handle::get_download_queue
torrent_handle::piece_availability

create_torrent::add_node() takes two arguments, one string and one integer, instead of a pair. The string is the address and the integer is the port.

session::set_settings() not only accepts a session_settings object, but also a dictionary with keys matching the names of the members of the session_settings struct. When calling set_settings, the dictionary does not need to have every settings set, keys that are not present, are set to their default value.

For backwards compatibility, session::settings() still returns a session_settings struct. To get a python dictionary of the settings, call session::get_settings.

For an example python program, see client.py in the bindings/python directory.

A very simple example usage of the module would be something like this:

import libtorrent as lt
import time

ses = lt.session()
ses.listen_on(6881, 6891)

e = lt.bdecode(open("test.torrent", 'rb').read())
info = lt.torrent_info(e)

params = { save_path: './', \
        storage_mode: lt.storage_mode_t.storage_mode_sparse, \
        ti: info }
h = ses.add_torrent(params)

while (not h.is_seed()):
        s = h.status()

        state_str = ['queued', 'checking', 'downloading metadata', \
                'downloading', 'finished', 'seeding', 'allocating']
        print '%.2f%% complete (down: %.1f kb/s up: %.1f kB/s peers: %d) %s' % \
                (s.progress * 100, s.download_rate / 1000, s.upload_rate / 1000, \
                s.num_peers, state_str[s.state])

        time.sleep(1)