Fix type hint for filepath (#9434)

Author: kaushikb11

pytorch_lightning/accelerators/accelerator.py

@@ -27,7 +27,7 @@
 from pytorch_lightning.utilities import _NATIVE_AMP_AVAILABLE
 from pytorch_lightning.utilities.apply_func import apply_to_collection, move_data_to_device
 from pytorch_lightning.utilities.enums import AMPType, GradClipAlgorithmType, LightningEnum
-from pytorch_lightning.utilities.types import STEP_OUTPUT
+from pytorch_lightning.utilities.types import _PATH, STEP_OUTPUT
 
 if _NATIVE_AMP_AVAILABLE:
     from torch.cuda.amp import GradScaler
@@ -392,7 +392,7 @@ def model_sharded_context(self) -> Generator[None, None, None]:
         with self.training_type_plugin.model_sharded_context():
             yield
 
-    def save_checkpoint(self, checkpoint: Dict[str, Any], filepath: str) -> None:
+    def save_checkpoint(self, checkpoint: Dict[str, Any], filepath: _PATH) -> None:
         """Save model/training states as a checkpoint file through state-dump and file-write.
 
         Args:

pytorch_lightning/plugins/training_type/training_type_plugin.py

@@ -26,7 +26,7 @@
 from pytorch_lightning.overrides.base import unwrap_lightning_module
 from pytorch_lightning.plugins import TorchCheckpointIO
 from pytorch_lightning.plugins.io.checkpoint_plugin import CheckpointIO
-from pytorch_lightning.utilities.types import _EVALUATE_OUTPUT, _PREDICT_OUTPUT
+from pytorch_lightning.utilities.types import _EVALUATE_OUTPUT, _PATH, _PREDICT_OUTPUT
 
 TBroadcast = TypeVar("T")
 
@@ -259,7 +259,7 @@ def lightning_module_state_dict(self) -> Dict[str, Union[Any, Tensor]]:
         model = self.lightning_module
         return model.state_dict()
 
-    def save_checkpoint(self, checkpoint: Dict[str, Any], filepath: str) -> None:
+    def save_checkpoint(self, checkpoint: Dict[str, Any], filepath: _PATH) -> None:
         """Save model/training states as a checkpoint file through state-dump and file-write.
 
         Args:
@@ -269,7 +269,7 @@ def save_checkpoint(self, checkpoint: Dict[str, Any], filepath: str) -> None:
         if self.should_rank_save_checkpoint:
             return self.checkpoint_io.save_checkpoint(checkpoint, filepath)
 
-    def remove_checkpoint(self, filepath: str) -> None:
+    def remove_checkpoint(self, filepath: _PATH) -> None:
         """Remove checkpoint filepath from the filesystem.
 
         Args:

pytorch_lightning/trainer/connectors/checkpoint_connector.py

@@ -26,6 +26,7 @@
 from pytorch_lightning.utilities.cloud_io import atomic_save, get_filesystem
 from pytorch_lightning.utilities.exceptions import MisconfigurationException
 from pytorch_lightning.utilities.imports import _fault_tolerant_training
+from pytorch_lightning.utilities.types import _PATH
 from pytorch_lightning.utilities.upgrade_checkpoint import KEYS_MAPPING as DEPRECATED_CHECKPOINT_KEYS
 
 if _OMEGACONF_AVAILABLE:
@@ -430,7 +431,7 @@ def get_max_ckpt_path_from_folder(self, folder_path: Union[str, Path]) -> str:
         ckpt_number = max_suffix if max_suffix is not None else 0
         return f"{folder_path}/hpc_ckpt_{ckpt_number}.ckpt"
 
-    def save_checkpoint(self, filepath, weights_only: bool = False) -> None:
+    def save_checkpoint(self, filepath: _PATH, weights_only: bool = False) -> None:
         """Save model/training states as a checkpoint file through state-dump and file-write.
 
         Args:

pytorch_lightning/trainer/properties.py

@@ -48,6 +48,7 @@
 )
 from pytorch_lightning.utilities.cloud_io import get_filesystem
 from pytorch_lightning.utilities.model_helpers import is_overridden
+from pytorch_lightning.utilities.types import _PATH
 
 
 class TrainerProperties(ABC):
@@ -388,7 +389,7 @@ def checkpoint_callbacks(self) -> List[ModelCheckpoint]:
     def resume_from_checkpoint(self) -> Optional[Union[str, Path]]:
         return self.checkpoint_connector.resume_checkpoint_path
 
-    def save_checkpoint(self, filepath, weights_only: bool = False) -> None:
+    def save_checkpoint(self, filepath: _PATH, weights_only: bool = False) -> None:
         self.checkpoint_connector.save_checkpoint(filepath, weights_only)
 
     """