import maya.cmds as cmds
import maya.mel as mel

# Get objList, first object, pivot position and parent of the first
objList = cmds.ls(selection=True, l=1)
firstObj = objList[0]
print (firstObj)
objPos = cmds.xform( firstObj, q=True, ws=True, rp=True ) 
objRot = cmds.xform( firstObj, q=True, ws=True, ro=True )
objPar = cmds.listRelatives(firstObj, parent=True, fullPath=True) 

tempCube = 'unique_placeholder_cube_delete'
cmds.polyCube(name=tempCube)
cmds.parent( tempCube, objPar)
cmds.select( objList)

locName = "tempLocNameDel"
#combine, rename and set pivot back
cmds.polyUnite()
lastName = firstObj.split("|")
nameInd = len(lastName)-1
print(lastName[nameInd])
cmds.rename(lastName[nameInd]) 
newObj = cmds.ls(selection=True, l=1 )
#Create temp locator, set its pivot to match first selected object, parent combined object to locator
spaceLoc = cmds.spaceLocator(name=locName)
cmds.move(objPos[0], objPos[1], objPos[2], locName)
cmds.rotate( objRot[0], objRot[1], objRot[2], locName)
cmds.select( newObj[0])
cmds.parent( newObj[0], locName ) 
#reset xform
cmds.makeIdentity( a=True, t=True, r=True, s=True )
cmds.xform(pivots=[objPos[0], objPos[1], objPos[2]], ws=True )

cmds.delete(constructionHistory=1)
objRef = cmds.ls(selection=True)

#If first object had a parent, parent it back, else try to find next parent in hierarchy
if objPar:
    cmds.parent( objRef, objPar)
else:
    cmds.parent( objRef, world=1)

cmds.delete( locName )
cmds.delete( tempCube )
mel.eval('setPolygonDisplaySettings("dispSoftEdge");')