From a5913b7c4a96aa483a18eb92df67ba7dba8eb1bb Mon Sep 17 00:00:00 2001
From: Hyukjin Kwon <gurwls223@apache.org>
Date: Tue, 23 Dec 2025 14:45:04 +0900
Subject: [PATCH] [Python] Add PyDecimal_Check(pythopn_decimal) as a
 ARROW_DCHECK

---
 python/pyarrow/src/arrow/python/decimal.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/python/pyarrow/src/arrow/python/decimal.cc b/python/pyarrow/src/arrow/python/decimal.cc
index 1ba8d32192a..48fb45a2377 100644
--- a/python/pyarrow/src/arrow/python/decimal.cc
+++ b/python/pyarrow/src/arrow/python/decimal.cc
@@ -51,9 +51,9 @@ static Status InferDecimalPrecisionAndScale(PyObject* python_decimal, int32_t* p
   ARROW_DCHECK_NE(python_decimal, NULLPTR);
   ARROW_DCHECK_NE(precision, NULLPTR);
   ARROW_DCHECK_NE(scale, NULLPTR);
+  ARROW_DCHECK(PyDecimal_Check(python_decimal))
+      << "python_decimal is not an instance of decimal.Decimal";
 
-  // TODO(phillipc): Make sure we perform PyDecimal_Check(python_decimal) as a
-  // ARROW_DCHECK
   OwnedRef as_tuple(PyObject_CallMethod(python_decimal, const_cast<char*>("as_tuple"),
                                         const_cast<char*>("")));
   RETURN_IF_PYERROR();