def desc(expr):
    if not isinstance(expr, Expr):
        return _ops.DeferredSortKey(expr, ascending=False)
    else:
        return _ops.SortKey(expr, ascending=False).to_expr()
Create a sort key (when used in sort_by) by the passed array expression or
dataset/ETHPy150Open cloudera/ibis/ibis/expr/api.py/desc