[API Compat] Add aliases for apis in paddle.optimizer.lr

Author: algorithm1832

python/paddle/optim/__init__.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from . import lr_scheduler
 from .adadelta import Adadelta
 from .adagrad import Adagrad
 from .adam import Adam
@@ -42,4 +43,5 @@
     "RMSProp",
     "Rprop",
     "SGD",
+    "lr_scheduler",
 ]

python/paddle/optim/lr_scheduler.py

@@ -0,0 +1,29 @@
+# Copyright (c) 2026 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from paddle.optimizer.lr import (
+    CosineAnnealingDecay as CosineAnnealingLR,  # noqa: F401
+    CosineAnnealingWarmRestarts as CosineAnnealingWarmRestarts,
+    CyclicLR as CyclicLR,
+    ExponentialDecay as ExponentialLR,  # noqa: F401
+    LambdaDecay as LambdaLR,  # noqa: F401
+    LinearLR as LinearLR,
+    LRScheduler as LRScheduler,
+    MultiplicativeDecay as MultiplicativeLR,  # noqa: F401
+    MultiStepDecay as MultiStepLR,  # noqa: F401
+    OneCycleLR as OneCycleLR,
+    PiecewiseDecay as ConstantLR,  # noqa: F401
+    ReduceOnPlateau as ReduceLROnPlateau,  # noqa: F401
+    StepDecay as StepLR,  # noqa: F401
+)

test/legacy_test/test_api_alias.py

@@ -187,12 +187,91 @@ def setUp(self):
                 paddle.optim.sgd.SGD,
                 None,
             ),
+            (
+                paddle.optimizer.lr.PiecewiseDecay,
+                paddle.optim.lr_scheduler.ConstantLR,
+                None,
+                None,
+            ),
+            (
+                paddle.optimizer.lr.CosineAnnealingDecay,
+                paddle.optim.lr_scheduler.CosineAnnealingLR,
+                None,
+                None,
+            ),
+            (
+                paddle.optimizer.lr.CosineAnnealingWarmRestarts,
+                paddle.optim.lr_scheduler.CosineAnnealingWarmRestarts,
+                None,
+                None,
+            ),
+            (
+                paddle.optimizer.lr.CyclicLR,
+                paddle.optim.lr_scheduler.CyclicLR,
+                None,
+                None,
+            ),
+            (
+                paddle.optimizer.lr.ExponentialDecay,
+                paddle.optim.lr_scheduler.ExponentialLR,
+                None,
+                None,
+            ),
+            (
+                paddle.optimizer.lr.LRScheduler,
+                paddle.optim.lr_scheduler.LRScheduler,
+                None,
+                None,
+            ),
+            (
+                paddle.optimizer.lr.LambdaDecay,
+                paddle.optim.lr_scheduler.LambdaLR,
+                None,
+                None,
+            ),
+            (
+                paddle.optimizer.lr.LinearLR,
+                paddle.optim.lr_scheduler.LinearLR,
+                None,
+                None,
+            ),
+            (
+                paddle.optimizer.lr.MultiStepDecay,
+                paddle.optim.lr_scheduler.MultiStepLR,
+                None,
+                None,
+            ),
+            (
+                paddle.optimizer.lr.MultiplicativeDecay,
+                paddle.optim.lr_scheduler.MultiplicativeLR,
+                None,
+                None,
+            ),
+            (
+                paddle.optimizer.lr.OneCycleLR,
+                paddle.optim.lr_scheduler.OneCycleLR,
+                None,
+                None,
+            ),
+            (
+                paddle.optimizer.lr.ReduceOnPlateau,
+                paddle.optim.lr_scheduler.ReduceLROnPlateau,
+                None,
+                None,
+            ),
+            (
+                paddle.optimizer.lr.StepDecay,
+                paddle.optim.lr_scheduler.StepLR,
+                None,
+                None,
+            ),
         ]
 
     def test_compatibility(self):
         for pairs in self.api_map:
             self.assertTrue(pairs[0], pairs[1])
-            self.assertTrue(pairs[0], pairs[2])
+            if pairs[2] is not None:
+                self.assertTrue(pairs[0], pairs[2])
             if pairs[3] is not None:
                 self.assertTrue(pairs[0], pairs[3])