Instructions for installing PyTorch

• I have searched the issues of this repo and believe that this is not a duplicate.

Issue

As mentioned in issue https://github.com/python-poetry/poetry/issues/4231 there is some confusion around installing PyTorch with CUDA but it is now somewhat resolved. It still requires a few steps, and all options have pretty serious flaws. Below are two options that 'worked' for me, on Poetry version 1.2.0.

Option 1 - wheel URLs for a specific platform

• You will need to pick the specific wheels you want. These are listed here: https://download.pytorch.org/whl/torch_stable.html. E.g. if you want CUDA 11.6, Python 3.10 and Windows, search that page for cu116-cp310-cp310-win_amd64.whl to see the matches for torch, torchaudio and torchvision
• In your pyproject.toml file add the URLs like:

[tool.poetry.dependencies]
python = "^3.10"
numpy = "^1.23.2"
torch = { url = "https://download.pytorch.org/whl/cu116/torch-1.12.1%2Bcu116-cp310-cp310-win_amd64.whl"}
torchaudio = { url = "https://download.pytorch.org/whl/cu116/torchaudio-0.12.1%2Bcu116-cp310-cp310-win_amd64.whl"}
torchvision = { url = "https://download.pytorch.org/whl/cu116/torchvision-0.13.1%2Bcu116-cp310-cp310-win_amd64.whl"}

• Run poetry update. It will download a lot of data (many GB) and take quite some time. And this doesn't seem to cache reliably (at least, I've waited 30 minutes+ at 56 Mbps three separate times while troubleshooting this, for the exact same wheels)

Note that each subsequent poetry update will do another huge download and you'll see this message:

  • Updating torch (1.12.1+cu116 -> 1.12.1+cu116 https://download.pytorch.org/whl/cu116/torch-1.12.1%2Bcu116-cp310-cp310-win_amd64.whl)
  • Updating torchaudio (0.12.1+cu116 -> 0.12.1+cu116 https://download.pytorch.org/whl/cu116/torchaudio-0.12.1%2Bcu116-cp310-cp310-win_amd64.whl)
  • Updating torchvision (0.13.1+cu116 -> 0.13.1+cu116 https://download.pytorch.org/whl/cu116/torchvision-0.13.1%2Bcu116-cp310-cp310-win_amd64.whl)

Option 2 - alternate source

[tool.poetry.dependencies]
python = "^3.10"
numpy = "^1.23.2"
torch = { version = "1.12.1", source="torch"}
torchaudio = { version = "0.12.1", source="torch"}
torchvision = { version = "0.13.1", source="torch"}

[[tool.poetry.source]]
name = "torch"
url = "https://download.pytorch.org/whl/cu116"
secondary = true

This seems to have worked (although I already had the packages installed) but it reports errors like Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/pillow/, but I think they get installed anyway (maybe a better message would be "Can't access pillow at 'https://download.pytorch.org/whl/cu116', falling back to pypi")

Also, if you later go on to do, say poetry add pandas (a completely unrelated library) you'll get a wall of messages like:

Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/pandas/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/pandas/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/pytz/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/python-dateutil/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/numpy/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/pillow/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/requests/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/typing-extensions/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/certifi/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/urllib3/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/idna/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/charset-normalizer/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/python-dateutil/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/six/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/pytz/
Source (torch): Authorization error accessing https://download.pytorch.org/whl/cu116/six/

This happens with or without secondary = true in the source config.

Maintainers: please feel free to edit the text of this if I've got something wrong.

Start with issue #4231, then review the pyproject.toml examples and the reported poetry update and poetry add pandas output. Reproduce the two installation approaches if possible and document the current supported guidance, including how the authorization messages should be understood; done means a newcomer can follow one verified path without relying on this long discussion.