Instead of putting the version just into setup.py, it would be great to make the version in use available through farm.__version__ as it is common practice with Python packages.

There are many ways to achieve this, one simple way is to have a file farm/_version.py which sets the variable __version__ to the version string and then import that variable into farm/__init__.py

The setup.py script could then load the version from farm/_version.py as well something similar to:

import os
import re
def versionfromfile(*filepath):
    infile = os.path.join(here, *filepath)
    with open(infile) as fp:
        version_match = re.search(
            r"^__version__\s*=\s*['\"]([^'\"]*)['\"]", fp.read(), re.M
        )
        if version_match:
            return version_match.group(1)
        raise RuntimeError("Unable to find version string in {}.".format(infile))

# ...

setup(..., version=versionfromfile("farm/_version.py"), ...)

Whenever the version number needs to get changed, the _version.py file is the only place to change.

(Also the version number could be set to something indiciating non-release versions at all times except when an actual version that gets released on pypi is getting tagged).

I find this approach quite useful and easy to implement in my own packages e.g. gatenlp and a number of popular projects are using similar approaches AFAIK.