使用python实现bt种子和磁力链接的相互转换

bt种子文件转换为磁力链接

bt种子文件相对磁力链来说存储不方便,而且在网站上存放bt文件容易引起版权纠纷,而磁力链相对来说则风险小一些。而且很多论坛或者网站限制了文件上传的类型,分享一个bt种子还需要改文件后缀或者压缩一次,其他人需要下载时候还要额外多一步下载种子的操作。

所以将bt种子转换为占用空间更小,分享更方便的磁力链还是有挺大好处的。

首先一个方案是使用bencode这个插件,通过pip方式安装或者自行下载源文件https://pypi.python.org/pypi/bencode/1.0通过python setup.py install方式安装均可。

相应的将bt种子转换为磁力链代码为:

import bencode, hashlib, base64, urllib
torrent = open(‘ubuntu-12.04.2-server-amd64.iso.torrent’, ‘rb’).read()
metadata = bencode.bdecode(torrent)
hashcontents = bencode.bencode(metadata[‘info’])
digest = hashlib.sha1(hashcontents).digest()
b32hash = base64.b32encode(digest)
params = {‘xt’: ‘urn:btih:%s’ % b32hash,
‘dn’: metadata[‘info’][‘name’],
‘tr’: metadata[‘announce’],
‘xl’: metadata[‘info’][‘length’]}
paramstr = urllib.urlencode(params)
magneturi = ‘magnet:?%s’ % paramstr
print magneturi

还有另外一个效率相对较高,而且更方便的方案是安装libtorrent,在ubuntu只需要apt-get install python-libtorrent即可对应转换磁力链的代码为:

import libtorrent as bt
info = bt.torrent_info(‘test.torrent’)
print “magnet:?xt=urn:btih:%s&dn=%s” % (info.info_hash(), info.name())

转换磁力链接为bt种子文件

下面来看一个反过程,将磁力链转化为种子文件。
1、需要先安装python-libtorrent包 ,在ubuntu环境下,可以通过以下指令完成安装:

# sudo apt-get install python-libtorrent

2、代码如下:

#!/usr/bin/env python
import shutil
import tempfile
import os.path as pt
import sys
import libtorrent as lt
from time import sleep
def magnet2torrent(magnet, output_name=none):
if output_name and \
not pt.isdir(output_name) and \
not pt.isdir(pt.dirname(pt.abspath(output_name))):
print(“invalid output folder: ” + pt.dirname(pt.abspath(output_name)))
print(“”)
sys.exit(0)
tempdir = tempfile.mkdtemp()
ses = lt.session()
params = {
‘save_path’: tempdir,
‘duplicate_is_error’: true,
‘storage_mode’: lt.storage_mode_t(2),
‘paused’: false,
‘auto_managed’: true,
‘duplicate_is_error’: true
}
handle = lt.add_magnet_uri(ses, magnet, params)
print(“downloading metadata (this may take a while)”)
while (not handle.has_metadata()):
try:
sleep(1)
except keyboardinterrupt:
print(“aborting…”)
ses.pause()
print(“cleanup dir ” + tempdir)
shutil.rmtree(tempdir)
sys.exit(0)
ses.pause()
print(“done”)
torinfo = handle.get_torrent_info()
torfile = lt.create_torrent(torinfo)
output = pt.abspath(torinfo.name() + “.torrent”)
if output_name:
if pt.isdir(output_name):
output = pt.abspath(pt.join(
output_name, torinfo.name() + “.torrent”))
elif pt.isdir(pt.dirname(pt.abspath(output_name))):
output = pt.abspath(output_name)
print(“saving torrent file here : ” + output + ” …”)
torcontent = lt.bencode(torfile.generate())
f = open(output, “wb”)
f.write(lt.bencode(torfile.generate()))
f.close()
print(“saved! cleaning up dir: ” + tempdir)
ses.remove_torrent(handle)
shutil.rmtree(tempdir)
return output
def showhelp():
print(“”)
print(“usage: ” + pt.basename(sys.argv[0]) + ” magnet [output]”)
print(” magnet\t- the magnet url”)
print(” output\t- the output torrent file name”)
print(“”)
def main():
if len(sys.argv) < 2: showhelp() sys.exit(0) magnet = sys.argv[1] output_name = none if len(sys.argv) >= 3:
output_name = sys.argv[2]
magnet2torrent(magnet, output_name)
if __name__ == “__main__”:
main()

3、用法如下

# python magnet_to_torrent2.py [torrent file]

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