[torchx/version] Make torchx.version.TORCHX_IMAGE follow the same semantics as __version__

[kiukchung]

Description

torchx.__version__ and torchx.__image__ should be consistent. Currently version is obtained by torchx.__version__ but image is torchx.version.TORCHX_IMAGE.

Detailed Proposal

Add import torchx.version.TORCHX_IMAGE to the root __init__.py file so that TORCHX_IMAGE can be referenced as torchx.__image__. (In addition we should make torchx.__version__ and torchx.__image__ reflect FB version and image when used internally (and not from github or pip)).

Motivation/Background

Once this is done we can change all references to TORCHX_IMAGE in the builtin components which would make them work in oss and also at fb (since presumably torchx.__image__ would point to ghcr.io docker image for oss and our internal package at fb).

Alternatives

N/A

Additional context/links

N/A

[d4l3k]

Generally __foo__ style strings are reserved for internal python known keywords. Could potentially be confusing if a user sees __image__ and assumes it's some builtin python language feature.

__version__ PEP for example https://www.python.org/dev/peps/pep-0396/

[kiukchung]

I see so if torchx.__image__ violates PEP standards just import TORCHX_IMAGE into init.py so that we can do torchx.TORCHX_IMAGE or torchx.IMAGE