migrate grouping to UDAF

Ref: apache/datafusion#10906

Author: Michael-J-Ward

python/datafusion/functions.py

@@ -1326,7 +1326,7 @@ def grouping(arg: Expr, distinct: bool = False) -> Expr:
 
     Returns 1 if the value of the argument is aggregated, 0 if not.
     """
-    return Expr(f.grouping([arg.expr], distinct=distinct))
+    return Expr(f.grouping(arg.expr, distinct=distinct))
 
 
 def max(arg: Expr, distinct: bool = False) -> Expr:

src/functions.rs

@@ -108,6 +108,16 @@ pub fn corr(y: PyExpr, x: PyExpr, distinct: bool) -> PyResult<PyExpr> {
     }
 }
 
+#[pyfunction]
+pub fn grouping(expression: PyExpr, distinct: bool) -> PyResult<PyExpr> {
+    let expr = functions_aggregate::expr_fn::grouping(expression.expr);
+    if distinct {
+        Ok(expr.distinct().build()?.into())
+    } else {
+        Ok(expr.into())
+    }
+}
+
 #[pyfunction]
 pub fn sum(args: PyExpr) -> PyExpr {
     functions_aggregate::expr_fn::sum(args.expr).into()
@@ -799,7 +809,6 @@ array_fn!(flatten, array);
 array_fn!(range, start stop step);
 
 aggregate_function!(array_agg, ArrayAgg);
-aggregate_function!(grouping, Grouping);
 aggregate_function!(max, Max);
 aggregate_function!(mean, Avg);
 aggregate_function!(min, Min);