def topk(arg, k, by=None):
    op = _ops.TopK(arg, k, by=by)
    return op.to_expr()
:param command_locator: A ``CommandLocator`` instance that
dataset/ETHPy150Open cloudera/ibis/ibis/expr/api.py/topk--crossover with--dataset/ETHPy150Open ClusterHQ/flocker/flocker/testtools/amp.py/LoopbackAMPClient.__init__