update deprecation message

Author: DuYicong515

pytorch_lightning/trainer/trainer.py

@@ -2017,8 +2017,8 @@ def num_processes(self) -> int:
     @property
     def root_gpu(self) -> Optional[int]:
         rank_zero_deprecation(
-            "`Trainer.root_gpu` is deprecated in v1.6 and will be removed in v1.8. Please use "
-            "`Trainer.strategy.root_device.index if isinstance(Trainer.accelerator, GPUAccelerator) else None` instead."
+            "`Trainer.root_gpu` is deprecated in v1.6 and will be removed in v1.8. "
+            "Please use `Trainer.strategy.root_device.index` instead."
         )
         return self.strategy.root_device.index if isinstance(self.accelerator, GPUAccelerator) else None
 

tests/deprecated_api/test_remove_1-8.py

@@ -895,8 +895,8 @@ def test_root_gpu_property(monkeypatch, gpus, expected_root_gpu, strategy):
     monkeypatch.setattr(torch.cuda, "is_available", lambda: True)
     monkeypatch.setattr(torch.cuda, "device_count", lambda: 16)
     with pytest.deprecated_call(
-        match="`Trainer.root_gpu` is deprecated in v1.6 and will be removed in v1.8. Please use "
-        r"`Trainer.strategy.root_device.index if isinstance\(Trainer.accelerator, GPUAccelerator\) else None` instead."
+        match="`Trainer.root_gpu` is deprecated in v1.6 and will be removed in v1.8. "
+        "Please use `Trainer.strategy.root_device.index` instead."
     ):
         assert Trainer(gpus=gpus, strategy=strategy).root_gpu == expected_root_gpu
 
@@ -912,7 +912,7 @@ def test_root_gpu_property(monkeypatch, gpus, expected_root_gpu, strategy):
 def test_root_gpu_property_0_passing(monkeypatch, gpus, expected_root_gpu, strategy):
     monkeypatch.setattr(torch.cuda, "device_count", lambda: 0)
     with pytest.deprecated_call(
-        match="`Trainer.root_gpu` is deprecated in v1.6 and will be removed in v1.8. Please use "
-        r"`Trainer.strategy.root_device.index if isinstance\(Trainer.accelerator, GPUAccelerator\) else None` instead."
+        match="`Trainer.root_gpu` is deprecated in v1.6 and will be removed in v1.8. "
+        "Please use `Trainer.strategy.root_device.index` instead."
     ):
         assert Trainer(gpus=gpus, strategy=strategy).root_gpu == expected_root_gpu