From b21bfb7684003c2188a277623a1fab5315e2eca0 Mon Sep 17 00:00:00 2001
From: mameikagou <mrlonely1226@163.com>
Date: Thu, 20 Aug 2026 15:39:39 +0800
Subject: [PATCH] fix(data): support unary expression negation

---
 qlib/data/base.py               |  5 +++++
 tests/ops/test_elem_operator.py | 13 +++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/qlib/data/base.py b/qlib/data/base.py
index 496ae38ee23..77109f1d87a 100644
--- a/qlib/data/base.py
+++ b/qlib/data/base.py
@@ -29,6 +29,11 @@ def __str__(self):
     def __repr__(self):
         return str(self)
 
+    def __neg__(self):
+        from .ops import Sub  # pylint: disable=C0415
+
+        return Sub(0, self)
+
     def __gt__(self, other):
         from .ops import Gt  # pylint: disable=C0415
 
diff --git a/tests/ops/test_elem_operator.py b/tests/ops/test_elem_operator.py
index 8349157ff44..399bffc0df9 100644
--- a/tests/ops/test_elem_operator.py
+++ b/tests/ops/test_elem_operator.py
@@ -39,6 +39,19 @@ def test_Sign(self):
         golden = change.to_numpy()
         self.assertIsNone(np.testing.assert_allclose(result, golden))
 
+    def test_unary_negation(self):
+        cases = [
+            ("-$close", "0 - $close"),
+            ("-Std($close, 3)", "0 - Std($close, 3)"),
+        ]
+        for field, equivalent in cases:
+            with self.subTest(field=field):
+                result = ExpressionD.expression(self.instrument, field, self.start_time, self.end_time, self.freq)
+                expected = ExpressionD.expression(
+                    self.instrument, equivalent, self.start_time, self.end_time, self.freq
+                )
+                np.testing.assert_allclose(result.to_numpy(), expected.to_numpy(), equal_nan=True)
+
 
 class TestOperatorDataSetting(TestOperatorData):
     def test_setting(self):