lightning/pytorch_lightning/callbacks/base.py

369 lines
14 KiB
Python

# Copyright The PyTorch Lightning team.
#
# 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.
r"""
Base class used to build new callbacks.
"""
from typing import Any, Dict, List, Optional, Type
import torch
from torch.optim import Optimizer
import pytorch_lightning as pl
from pytorch_lightning.utilities.types import STEP_OUTPUT
class Callback:
r"""
Abstract base class used to build new callbacks.
Subclass this class and override any of the relevant hooks
"""
@property
def state_key(self) -> str:
"""Identifier for the state of the callback.
Used to store and retrieve a callback's state from the checkpoint dictionary by
``checkpoint["callbacks"][state_key]``. Implementations of a callback need to provide a unique state key if 1)
the callback has state and 2) it is desired to maintain the state of multiple instances of that callback.
"""
return self.__class__.__qualname__
@property
def _legacy_state_key(self) -> Type["Callback"]:
"""State key for checkpoints saved prior to version 1.5.0."""
return type(self)
def _generate_state_key(self, **kwargs: Any) -> str:
"""Formats a set of key-value pairs into a state key string with the callback class name prefixed. Useful
for defining a :attr:`state_key`.
Args:
**kwargs: A set of key-value pairs. Must be serializable to :class:`str`.
"""
return f"{self.__class__.__qualname__}{repr(kwargs)}"
def on_configure_sharded_model(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
r"""
.. deprecated:: v1.6
This callback hook was deprecated in v1.6 and will be removed in v1.8. Use `setup()` instead.
Called before configure sharded model.
"""
def on_before_accelerator_backend_setup(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
r"""
.. deprecated:: v1.6
This callback hook was deprecated in v1.6 and will be removed in v1.8. Use ``setup()`` instead.
Called before accelerator is being setup.
"""
def setup(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", stage: Optional[str] = None) -> None:
"""Called when fit, validate, test, predict, or tune begins."""
def teardown(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", stage: Optional[str] = None) -> None:
"""Called when fit, validate, test, predict, or tune ends."""
def on_init_start(self, trainer: "pl.Trainer") -> None:
r"""
.. deprecated:: v1.6
This callback hook was deprecated in v1.6 and will be removed in v1.8.
Called when the trainer initialization begins, model has not yet been set.
"""
def on_init_end(self, trainer: "pl.Trainer") -> None:
r"""
.. deprecated:: v1.6
This callback hook was deprecated in v1.6 and will be removed in v1.8.
Called when the trainer initialization ends, model has not yet been set.
"""
def on_fit_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when fit begins."""
def on_fit_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when fit ends."""
def on_sanity_check_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the validation sanity check starts."""
def on_sanity_check_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the validation sanity check ends."""
def on_train_batch_start(
self,
trainer: "pl.Trainer",
pl_module: "pl.LightningModule",
batch: Any,
batch_idx: int,
unused: int = 0,
) -> None:
"""Called when the train batch begins."""
def on_train_batch_end(
self,
trainer: "pl.Trainer",
pl_module: "pl.LightningModule",
outputs: STEP_OUTPUT,
batch: Any,
batch_idx: int,
unused: int = 0,
) -> None:
"""Called when the train batch ends."""
def on_train_epoch_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the train epoch begins."""
def on_train_epoch_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the train epoch ends.
To access all batch outputs at the end of the epoch, either:
1. Implement `training_epoch_end` in the `LightningModule` and access outputs via the module OR
2. Cache data across train batch hooks inside the callback implementation to post-process in this hook.
"""
def on_validation_epoch_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the val epoch begins."""
def on_validation_epoch_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the val epoch ends."""
def on_test_epoch_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the test epoch begins."""
def on_test_epoch_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the test epoch ends."""
def on_predict_epoch_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the predict epoch begins."""
def on_predict_epoch_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", outputs: List[Any]) -> None:
"""Called when the predict epoch ends."""
def on_epoch_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
r"""
.. deprecated:: v1.6
This callback hook was deprecated in v1.6 and will be removed in v1.8. Use
``on_<train/validation/test>_epoch_start`` instead.
Called when either of train/val/test epoch begins.
"""
def on_epoch_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
r"""
.. deprecated:: v1.6
This callback hook was deprecated in v1.6 and will be removed in v1.8. Use
``on_<train/validation/test>_epoch_end`` instead.
Called when either of train/val/test epoch ends.
"""
def on_batch_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
r"""
.. deprecated:: v1.6
This callback hook was deprecated in v1.6 and will be removed in v1.8. Use
``on_train_batch_start`` instead.
Called when the training batch begins.
"""
def on_batch_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
r"""
.. deprecated:: v1.6
This callback hook was deprecated in v1.6 and will be removed in v1.8. Use
``on_train_batch_end`` instead.
Called when the training batch ends.
"""
def on_validation_batch_start(
self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", batch: Any, batch_idx: int, dataloader_idx: int
) -> None:
"""Called when the validation batch begins."""
def on_validation_batch_end(
self,
trainer: "pl.Trainer",
pl_module: "pl.LightningModule",
outputs: Optional[STEP_OUTPUT],
batch: Any,
batch_idx: int,
dataloader_idx: int,
) -> None:
"""Called when the validation batch ends."""
def on_test_batch_start(
self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", batch: Any, batch_idx: int, dataloader_idx: int
) -> None:
"""Called when the test batch begins."""
def on_test_batch_end(
self,
trainer: "pl.Trainer",
pl_module: "pl.LightningModule",
outputs: Optional[STEP_OUTPUT],
batch: Any,
batch_idx: int,
dataloader_idx: int,
) -> None:
"""Called when the test batch ends."""
def on_predict_batch_start(
self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", batch: Any, batch_idx: int, dataloader_idx: int
) -> None:
"""Called when the predict batch begins."""
def on_predict_batch_end(
self,
trainer: "pl.Trainer",
pl_module: "pl.LightningModule",
outputs: Any,
batch: Any,
batch_idx: int,
dataloader_idx: int,
) -> None:
"""Called when the predict batch ends."""
def on_train_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the train begins."""
def on_train_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the train ends."""
def on_pretrain_routine_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
r"""
.. deprecated:: v1.6
This callback hook was deprecated in v1.6 and will be removed in v1.8. Use ``on_fit_start`` instead.
Called when the pretrain routine begins.
"""
def on_pretrain_routine_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
r"""
.. deprecated:: v1.6
This callback hook was deprecated in v1.6 and will be removed in v1.8. Use ``on_fit_start`` instead.
Called when the pretrain routine ends.
"""
def on_validation_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the validation loop begins."""
def on_validation_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the validation loop ends."""
def on_test_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the test begins."""
def on_test_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the test ends."""
def on_predict_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when the predict begins."""
def on_predict_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called when predict ends."""
def on_keyboard_interrupt(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
r"""
.. deprecated:: v1.5
This callback hook was deprecated in v1.5 in favor of `on_exception` and will be removed in v1.7.
Called when any trainer execution is interrupted by KeyboardInterrupt.
"""
def on_exception(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", exception: BaseException) -> None:
"""Called when any trainer execution is interrupted by an exception."""
def state_dict(self) -> Dict[str, Any]:
"""Called when saving a checkpoint, implement to generate callback's ``state_dict``.
Returns:
A dictionary containing callback state.
"""
return {}
def load_state_dict(self, state_dict: Dict[str, Any]) -> None:
"""Called when loading a checkpoint, implement to reload callback state given callback's ``state_dict``.
Args:
state_dict: the callback state returned by ``state_dict``.
"""
pass
def on_save_checkpoint(
self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", checkpoint: Dict[str, Any]
) -> Optional[dict]:
r"""
Called when saving a checkpoint to give you a chance to store anything else you might want to save.
Args:
trainer: the current :class:`~pytorch_lightning.trainer.Trainer` instance.
pl_module: the current :class:`~pytorch_lightning.core.lightning.LightningModule` instance.
checkpoint: the checkpoint dictionary that will be saved.
Returns:
None or the callback state. Support for returning callback state will be removed in v1.8.
.. deprecated:: v1.6
Returning a value from this method was deprecated in v1.6 and will be removed in v1.8.
Implement ``Callback.state_dict`` instead to return state.
In v1.8 ``Callback.on_save_checkpoint`` can only return None.
"""
def on_load_checkpoint(
self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", callback_state: Dict[str, Any]
) -> None:
r"""
Called when loading a model checkpoint, use to reload state.
Args:
trainer: the current :class:`~pytorch_lightning.trainer.Trainer` instance.
pl_module: the current :class:`~pytorch_lightning.core.lightning.LightningModule` instance.
callback_state: the callback state returned by ``on_save_checkpoint``.
Note:
The ``on_load_checkpoint`` won't be called with an undefined state.
If your ``on_load_checkpoint`` hook behavior doesn't rely on a state,
you will still need to override ``on_save_checkpoint`` to return a ``dummy state``.
.. deprecated:: v1.6
This callback hook will change its signature and behavior in v1.8.
If you wish to load the state of the callback, use ``Callback.load_state_dict`` instead.
In v1.8 ``Callback.on_load_checkpoint(checkpoint)`` will receive the entire loaded
checkpoint dictionary instead of only the callback state from the checkpoint.
"""
def on_before_backward(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", loss: torch.Tensor) -> None:
"""Called before ``loss.backward()``."""
def on_after_backward(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
"""Called after ``loss.backward()`` and before optimizers are stepped."""
def on_before_optimizer_step(
self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", optimizer: Optimizer, opt_idx: int
) -> None:
"""Called before ``optimizer.step()``."""
def on_before_zero_grad(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", optimizer: Optimizer) -> None:
"""Called before ``optimizer.zero_grad()``."""