Cast inputs to true division from decimal to float

python/cudf_polars/cudf_polars/dsl/translate.py

@@ -919,13 +919,30 @@ def _(
     dtype: DataType,
     schema: Schema,
 ) -> expr.Expr:
+    left = translator.translate_expr(n=node.left, schema=schema)
+    right = translator.translate_expr(n=node.right, schema=schema)
     if plc.traits.is_boolean(dtype.plc_type) and node.op == pl_expr.Operator.TrueDivide:
         dtype = DataType(pl.Float64())
+    if node.op == pl_expr.Operator.TrueDivide and (
+        plc.traits.is_fixed_point(left.dtype.plc_type)
+        or plc.traits.is_fixed_point(right.dtype.plc_type)
+    ):
+        f64 = DataType(pl.Float64())
+        return expr.Cast(
+            dtype,
+            expr.BinOp(
+                f64,
+                expr.BinOp._MAPPING[node.op],
+                expr.Cast(f64, left),
+                expr.Cast(f64, right),
+            ),
+        )
+
     return expr.BinOp(
         dtype,
         expr.BinOp._MAPPING[node.op],
-        translator.translate_expr(n=node.left, schema=schema),
-        translator.translate_expr(n=node.right, schema=schema),
+        left,
+        right,
     )
 
 

python/cudf_polars/tests/expressions/test_numeric_binops.py

@@ -2,13 +2,16 @@
 # SPDX-License-Identifier: Apache-2.0
 from __future__ import annotations
 
+from decimal import Decimal
+
 import pytest
 
 import polars as pl
 
 from cudf_polars.testing.asserts import (
     assert_gpu_result_equal,
 )
+from cudf_polars.utils.versions import POLARS_VERSION_LT_132
 
 dtypes = [
     pl.Int8,
@@ -106,3 +109,15 @@ def test_true_div_boolean_column(divisor):
     q = df.select(pl.col("a") / divisor)
 
     assert_gpu_result_equal(q)
+
+
+def test_true_div_with_decimals():
+    df = pl.LazyFrame(
+        {
+            "foo": [Decimal("1.00"), Decimal("2.00"), Decimal("3.00"), None],
+            "bar": [Decimal("4.00"), Decimal("5.00"), Decimal("6.00"), Decimal("1.00")],
+        },
+        schema={"foo": pl.Decimal(15, 2), "bar": pl.Decimal(15, 2)},
+    )
+    q = df.select(pl.col("bar") / pl.col("foo"))
+    assert_gpu_result_equal(q, check_dtypes=not POLARS_VERSION_LT_132)