controlShapeReplacer.py

def shapeReplacer(obj, crv):
    selection=[]
    shape=[]
    if(obj == ""):
        selection = cmds.ls(sl=True)
    else:
        selection = obj
    shape = cmds.listRelatives(selection, f=True,s=True)
    #this split to make sure that we don't delete shapes we are using for common controls added from the 'shapeParent' function
    #those shapes return as separate strings in the same list index for some maya reason
    x = shape[0].split(",")
    if(len(shape)>0):
        cmds.delete(x)
    replacementShape = cmds.listRelatives(crv, f=True,s=True)
    cmds.parent(replacementShape, selection, shape = True, add = True)
    cmds.delete(crv)