An Open In handler for Pythonista that uploads the file which name was passed to the configured server via SFTP, then runs the configured command on that server (e.g., transmission add).

TransmissionClient

import console
import paramiko
import keychain
import traceback
from os.path import basename


# TransmissionClient
#
# An Open In handler that uploads the file which name was passed
# to the configured server via SFTP, then runs the configured
# command on that server (e.g., transmission add).
#
# To start using, configure the constants below, then run
# the script once to save the password in the keychain.
# Then, in the Open In script, run 
# TransmissionClient.upload(torrent_file_path)

# Configuration
HOST = 'server'
USERNAME = 'oleg'  # $1 below is replaced with torrent file basename
ADD_CMD = './transmission-remote-cli.py -f .trclirc -- -a "$1"'
CLEAN_CMD = 'rm "$1"'


def open_connection():
    ssh = paramiko.SSHClient()
    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    password = keychain.get_password('ssh:' + HOST, USERNAME)
    console.set_color(0, 0, 1)
    print 'connecting to %s@%s...' % (USERNAME, HOST)
    console.set_color(0, 0, 0)
    ssh.connect(HOST, username=USERNAME, password=password)
    return ssh

def run_cmd(ssh, cmd):
    console.set_color(0, 0, 1)
    print '[remote] $ %s' % cmd
    console.set_color(0, 0, 0)
    stdin, stdout, stderr = ssh.exec_command(cmd)
    data = stdout.read()
    print data

def do_upload(ssh, torrent_filename):
    bn = basename(torrent_filename)
    ftp = ssh.open_sftp()
    console.set_color(0, 0, 1)
    print 'uploading ' + bn
    console.set_color(0, 0, 0)
    ftp.put(torrent_filename, bn)
    ftp.close()
    return bn

def upload(torrent_filename):
    ssh = None
    try:
        console.show_activity()
        ssh = open_connection()
        bn = do_upload(ssh, torrent_filename)
        run_cmd(ssh, ADD_CMD.replace('$1', bn))
        run_cmd(ssh, CLEAN_CMD.replace('$1', bn))
        console.hud_alert(bn + ' uploaded and started')
    except Exception as ex:
        console.set_color(1, 0, 0)
        traceback.print_exc()
        console.set_color(0, 0, 0)
        console.alert('Torrent Upload Failed', str(ex))
    finally:
        if ssh:
            ssh.close()
        console.hide_activity()

def add_to_keychain():
    try:
        password = console.password_alert(
            'Configure Connection Password',
            'Please enter the password for %s@%s.\n\n' % (USERNAME, HOST) +
            'The password will be saved in the keychain and used to ' +
            'connect to this server via SSH.')
        keychain.set_password('ssh:' + HOST, USERNAME, password)
        console.show_activity()
        console.hud_alert('Saved, now verifying')
        ssh = open_connection()
        ssh.close()
        console.hud_alert('Password is correct')
    except KeyboardInterrupt:
        # user cancelled the operation
        pass
    except (paramiko.AuthenticationException, paramiko.SSHException) as ex:
        console.alert(
            'Password Incorrect', 
            'Cannot connect to the server using the provided password.\n' + str(ex))
    finally:
        console.hide_activity()

if __name__ == '__main__':
    add_to_keychain()