Pytorch-lightning: AttributeError: module 'pytorch_lightning' has no attribute 'TrainResult'

[francoisruty]

🐛 Bug

Following https://pytorch-lightning.readthedocs.io/en/latest/new-project.html
I tried to log loss values to Tensorboard:

def training_step(self, batch, batch_idx):
loss = ...
result = pl.TrainResult(minimize=loss)
result.log('train_loss', loss)
return result

It seems module "TrainResult" is not present in pytorch-lighting, I'm using latest version (0.8.5)

After browsing various github and SO issues I tried
import TrainResult from pytorch_lightning

but it still doesn't work

To Reproduce

Just follow example in https://pytorch-lightning.readthedocs.io/en/latest/new-project.html

def training_step(self, batch, batch_idx):
loss = ...
result = pl.TrainResult(minimize=loss)
result.log('train_loss', loss)
return result

Expected behavior

I expect code sample in documentation to work (not crash when importing a pytorch-lightning module)

Environment

• PyTorch Version (e.g., 1.0): 1.5.0
• OS (e.g., Linux): linux
• How you installed PyTorch (conda, pip, source): pip
• Build command you used (if compiling from source): N/A
• Python version: 3.6.9
• CUDA/cuDNN version: docker image nvidia/cuda:10.2-cudnn7-devel-ubuntu18.04
• GPU models and configuration: Nvidia GTI 1080

[github-actions[bot]]

Hi! thanks for your contribution!, great first issue!

[francoisruty]

import pytorch_lightning as pl
pl.TrainResult
--> fails

from pytorch_lightning import Trainer, TrainResult
--> fails

[francoisruty]

Same for pytorch-lightning 8.4 and 8.3
Seems fixed on 0.9.0rc12

[williamFalcon]

it's a new feature of 0.9.0 not available before

[francoisruty]

@williamFalcon
hello, ok, however may I suggest to version differently https://pytorch-lightning.readthedocs.io documentation?

At the moment default homepage is https://pytorch-lightning.readthedocs.io/en/latest/
Since it seems pytorch lightning team uses "latest" as "real latest" and not "latest stable version", it means the default documentation content presented by Google may significantly differ from what's possible in the version one might install by default from Pypi (which would be the latest stable version for production-oriented people like me, which is the version displayed on pypi pytorch-lightning homepage)

[williamFalcon]

where is this link set in the homepage?

[francoisruty]

https://pypi.org/project/pytorch-lightning/
https://pytorch-lightning.readthedocs.io/en/latest/. --> referenced on above link