lightning/tests/tests_pytorch/trainer/optimization/test_multiple_optimizers.py

88 lines
2.9 KiB
Python

# Copyright The Lightning AI 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.
"""Tests to ensure that the behaviours related to multiple optimizers works."""
import lightning.pytorch as pl
import pytest
import torch
from lightning.pytorch.demos.boring_classes import BoringModel
class MultiOptModel(BoringModel):
def configure_optimizers(self):
opt_a = torch.optim.SGD(self.layer.parameters(), lr=0.001)
opt_b = torch.optim.SGD(self.layer.parameters(), lr=0.001)
return opt_a, opt_b
def test_multiple_optimizers_automatic_optimization_raises():
"""Test that multiple optimizers in automatic optimization is not allowed."""
class TestModel(BoringModel):
def training_step(self, batch, batch_idx, optimizer_idx):
return super().training_step(batch, batch_idx)
model = TestModel()
model.automatic_optimization = True
trainer = pl.Trainer()
with pytest.raises(RuntimeError, match="Remove the `optimizer_idx` argument from `training_step`"):
trainer.fit(model)
class TestModel(BoringModel):
def configure_optimizers(self):
return torch.optim.Adam(self.parameters()), torch.optim.Adam(self.parameters())
model = TestModel()
model.automatic_optimization = True
trainer = pl.Trainer()
with pytest.raises(RuntimeError, match="multiple optimizers is only supported with manual optimization"):
trainer.fit(model)
def test_multiple_optimizers_manual(tmpdir):
class TestModel(MultiOptModel):
def __init__(self):
super().__init__()
self.automatic_optimization = False
def training_step(self, batch, batch_idx):
self.training_step_called = True
# manual optimization
opt_a, opt_b = self.optimizers()
loss_1 = self.step(batch[0])
# fake generator
self.manual_backward(loss_1)
opt_a.step()
opt_a.zero_grad()
# fake discriminator
loss_2 = self.step(batch[0])
self.manual_backward(loss_2)
opt_b.step()
opt_b.zero_grad()
model = TestModel()
model.val_dataloader = None
trainer = pl.Trainer(
default_root_dir=tmpdir, limit_train_batches=2, max_epochs=1, log_every_n_steps=1, enable_model_summary=False
)
trainer.fit(model)
assert model.training_step_called