Installing Lite also installs PyTorch Lightning

[carmocca]

Proposed refactor

See title

Motivation

$ python -c "import pytorch_lightning"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ModuleNotFoundError: No module named 'pytorch_lightning'

$ PACKAGE_NAME=lite pip install -e .
...
Successfully installed lightning-lite-1.8.0.post1

$ python -c "import pytorch_lightning"
$ echo $?
0

Pitch

PL should not be included.

---

If you enjoy Lightning, check out our other projects! ⚡

• Metrics: Machine learning metrics for distributed, scalable PyTorch applications.

• Lite: enables pure PyTorch users to scale their existing code on any kind of device while retaining full control over their own loops and optimization logic.

• Flash: The fastest way to get a Lightning baseline! A collection of tasks for fast prototyping, baselining, fine-tuning, and solving problems with deep learning.

• Bolts: Pretrained SOTA Deep Learning models, callbacks, and more for research and production with PyTorch Lightning and PyTorch.

• Lightning Transformers: Flexible interface for high-performance research using SOTA Transformers leveraging PyTorch Lightning, Transformers, and Hydra.

cc @carmocca @akihironitta @Borda

[carmocca]

This is caused by using -e. When it's used, lightning/src is added to sys.path:

$ python -m site
sys.path = [
    ...,
    '/home/carmocca/git/lightning/src',
]

And since that directory contains the other packages, they become importable.

This is not only with Lite, also when any of them is installed with editable mode.