def split(oEditor, partlist, 
          NewPartsModelFlag="Model", 
          SplitPlane='XY', 
          WhichSide="PositiveOnly", 
          SplitCrossingObjectsOnly=False, 
          DeleteInvalidObjects=True):
    """
    Splits specified objects along a plane.
    
    Parameters
    ----------
    oEditor : pywin32 COMObject
        The HFSS editor in which the operation will be performed.
    partlist : list
        List of part name strings to be mirrored.
    SplitPlane : str
        Plane in which to split the part(s).  Allowable values are "XY", "ZX", or "YZ"
    WhichSide : str
        Side to keep.  Allowable values are "Both", "PositiveOnly", or "NegativeOnly"
    SplitCrossingObjectsOnly : bool
        If True, only splits objects that actually cross the split plane.
    DeleteInvalidObjects : bool
        If True, invalid objects generated by the operation are deleted.
        
    Returns
    -------
    None
    """
    selectionsarray = ["NAME:Selections", 
                       "Selections:=", ",".join(partlist), 
                       "NewPartsModelFlag:=", NewPartsModelFlag]
    splittoparams = ["NAME:SplitToParameters", 
                     "SplitPlane:=", SplitPlane, 
                     "WhichSide:=", WhichSide, 
                     "SplitCrossingObjectsOnly:=", SplitCrossingObjectsOnly, 
                     "DeleteInvalidObjects:=", DeleteInvalidObjects]
                       
    return oEditor.Split(selectionsarray, splittoparams)