def _isgroup(obj, *args, **kws):
    _larch = kws.get('_larch', None)
    if _larch is None:
        raise Warning("cannot run isgroup() -- larch broken?")
    stable = _larch.symtable
    if isinstance(obj, (str, unicode)) and stable.has_symbol(obj):
        obj = stable.get_symbol(obj)
    return isgroup(obj, *args)
return whether argument is a group or the name of a group
dataset/ETHPy150Open xraypy/xraylarch/lib/builtins.py/_isgroup