def is_zpk(zpktup):
return (<EOL>isinstance(zpktup, (tuple, list)) and<EOL>len(zpktup) == <NUM_LIT:3> and<EOL>isinstance(zpktup[<NUM_LIT:0>], (list, tuple, numpy.ndarray)) and<EOL>isinstance(zpktup[<NUM_LIT:1>], (list, tuple, numpy.ndarray)) and<EOL>isinstance(zpktup[<NUM_LIT:2>], float))<EOL>
Determin whether the given tuple is a ZPK-format filter definition

    Returns
    -------
    iszpk : `bool`
        `True` if the ``zpktup`` looks like a ZPK-format filter definition,
        otherwise `False`