Return module *modname* data path
    Note: relpath is ignored if module has an attribute named *attr_name*
    
    Handles py2exe/cx_Freeze distributions

def get_module_data_path(modname, relpath=None, attr_name='DATAPATH'):
    """Return module *modname* data path
    Note: relpath is ignored if module has an attribute named *attr_name*
    
    Handles py2exe/cx_Freeze distributions"""
    datapath = getattr(sys.modules[modname], attr_name, '')
    if datapath:
        return datapath
    else:
        datapath = get_module_path(modname)
        parentdir = osp.join(datapath, osp.pardir)
        if osp.isfile(parentdir):
            # Parent directory is not a directory but the 'library.zip' file:
            # this is either a py2exe or a cx_Freeze distribution
            datapath = osp.abspath(osp.join(osp.join(parentdir, osp.pardir),
                                            modname))
        if relpath is not None:
            datapath = osp.abspath(osp.join(datapath, relpath))
        return datapath