From 2abb4dac24c41cb58c6c73023ecc6dfeb4c694cd Mon Sep 17 00:00:00 2001
From: Michael Panchenko <m.panchenko@appliedai.de>
Date: Sun, 5 May 2024 22:23:13 +0200
Subject: [PATCH] Reinstated warning module

---
 tianshou/utils/__init__.py | 2 ++
 tianshou/utils/warning.py  | 8 ++++++++
 2 files changed, 10 insertions(+)
 create mode 100644 tianshou/utils/warning.py

diff --git a/tianshou/utils/__init__.py b/tianshou/utils/__init__.py
index 2f46f9c..47a3c44 100644
--- a/tianshou/utils/__init__.py
+++ b/tianshou/utils/__init__.py
@@ -6,11 +6,13 @@ from tianshou.utils.logger.wandb import WandbLogger
 from tianshou.utils.lr_scheduler import MultipleLRSchedulers
 from tianshou.utils.progress_bar import DummyTqdm, tqdm_config
 from tianshou.utils.statistics import MovAvg, RunningMeanStd
+from tianshou.utils.warning import deprecation
 
 __all__ = [
     "MovAvg",
     "RunningMeanStd",
     "tqdm_config",
+    "deprecation",
     "DummyTqdm",
     "BaseLogger",
     "TensorboardLogger",
diff --git a/tianshou/utils/warning.py b/tianshou/utils/warning.py
new file mode 100644
index 0000000..93c5cce
--- /dev/null
+++ b/tianshou/utils/warning.py
@@ -0,0 +1,8 @@
+import warnings
+
+warnings.simplefilter("once", DeprecationWarning)
+
+
+def deprecation(msg: str) -> None:
+    """Deprecation warning wrapper."""
+    warnings.warn(msg, category=DeprecationWarning, stacklevel=2)