urx is a python library to control a robot from 'Universal robot'.
Internally, to control the robots, urx uses both the 'secondary port' interface and the real-time/matlab interface. 
urx can optionally use the python-math3d https://launchpad.net/pymath3d library to receive and send transformation matrices to the robot
Example use:

import urx

rob = urx.robot("192.168.0.100")
rob.set_tcp((x=01, z=0.232))
rob.movej((1,2,3,4,5,6), a, v) # move in robot internal coordinate system
rob.movel((x,y,z,a,b,c), a, v)
print "Current tool pose is: ",  rob.getl()
rob.movel((0.1, 0, 0, 0, 0, 0), a, v, relative=true)# move relative to current pose
rob.translate((0.1, 0, 0), a, v) #move tool and keep orientation
rob.orient((0.1, 0, 0), a, v) #orient tool and keep tool tip position
rob.stopj(a)

robot.movel(x,y,z,a,b,c), wait=False)
while True :
    sleep(0.1) #sleep first since the information may be outdated
    if robot.is_program_running():
        break

robot.movel(x,y,z,a,b,c), wait=False)
while.robot.getForce() < 50:
    sleep(0.01)
robot.stopl()

try:
    robot.movel((0,0,0.1,0,0,0), relative=True)
except RobotError, ex:
    print "Robot could not execute move (emergency stop for example), do something", ex

Using matrices:

robot = Robot("192.168.1.1")
robot.set_tcp((0,0,0.23,0,0,0)
calib = mathd3d.Transform() 
calib.orient.rotate_zb(pi/4) #just an example
robot.set_calibration_matrix(calib) #set robot corrdinate system

trans = robot.get_transform() # get current transformation matrix (tool to base)
trans.orient.rotate_yt(pi/2)
robot.apply_transform(trans)
trans.pos += math3d.Vector(0,0,0.3)
robot.apply_transform(trans)


#or only work with orientation part
o = robot.get_orientation()
o.rotate_yb(pi)
robot.orient(o)



   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

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    but WITHOUT ANY WARRANTY; without even the implied warranty of
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    GNU General Public License for more details.

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