Source code for lightning.pytorch.callbacks.on_exception_checkpoint
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# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
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# http://www.apache.org/licenses/LICENSE-2.0
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"""
On exception checkpointing
==========================
Automatically save a checkpoints on exception.
"""
import os
from typing import Any
from typing_extensions import override
import lightning.pytorch as pl
from lightning.fabric.utilities.types import _PATH
from lightning.pytorch.callbacks import Checkpoint
[docs]class OnExceptionCheckpoint(Checkpoint):
"""Used to save a checkpoint on exception.
Args:
dirpath: directory to save the checkpoint file.
filename: checkpoint filename. This must not include the extension.
Raises:
ValueError:
If ``filename`` is empty.
Example:
>>> from lightning.pytorch import Trainer
>>> from lightning.pytorch.callbacks import OnExceptionCheckpoint
>>> trainer = Trainer(callbacks=[OnExceptionCheckpoint(".")])
"""
FILE_EXTENSION = ".ckpt"
def __init__(self, dirpath: _PATH, filename: str = "on_exception") -> None:
super().__init__()
if not filename:
raise ValueError("The filename cannot be empty")
# not optional because an exception could occur at any moment, so we cannot wait until the `setup` hook
self.dirpath = dirpath
self.filename = filename
@property
def ckpt_path(self) -> str:
return os.path.join(self.dirpath, self.filename + self.FILE_EXTENSION)
[docs] @override
def on_exception(self, trainer: "pl.Trainer", *_: Any, **__: Any) -> None:
# overwrite if necessary
trainer.save_checkpoint(self.ckpt_path)
[docs] @override
def teardown(self, trainer: "pl.Trainer", *_: Any, **__: Any) -> None:
trainer.strategy.remove_checkpoint(self.ckpt_path)