http://cafe.naver.com/digitaldream/2355
import maya.OpenMaya as om
import maya.cmds as cmds
import math
object1 =cmds.ls( 'object1' )[0]
objR = cmds.getAttr( object1 + '.r' )[0]
eulerRot = om.MEulerRotation( math.radians( objR[0] ), math.radians( objR[1] ), math.radians( objR[2] ) )
quat = eulerRot.asQuaternion()
print quat.x, quat.y, quat.z, quat.w