deploy.sh

## <project root>/ops/deploy.sh

PROJECT_ROOT=`git rev-parse --show-toplevel`
VERSION_FILE="$PROJECT_ROOT/atari_archive/VERSION"

# <rest of deploy script>

# Create version file based on tag or branch being deployed.
VERSION_STRING="$TAG_OR_BRANCH"
echo ">>>>> Creating VERSION file containing '$VERSION_STRING'..."
echo $VERSION_STRING > $VERSION_FILE
echo

setup.py

## <project root>/setup.py

# Duplicate this here since setup.py doesn't (and probably shouldn't) import anything from the package it's packaging.
VERSION_FILE = os.path.join(os.path.dirname(__file__), "atari_archive", "VERSION")
def version_from_file():
    if not os.path.exists(VERSION_FILE):
        return None

    with open(VERSION_FILE) as fd:
        return fd.read().strip()

setup(
    name='atari_archive',
    version=version_from_file() or "DEV",
# <rest of setup>

version.py

## <project root>/atari_archive/version.py

import os

# Created by deploy script.
VERSION_FILE = os.path.join(os.path.dirname(__file__), "VERSION")

def version_from_file():
    if not os.path.exists(VERSION_FILE):
        return None

    with open(VERSION_FILE) as fd:
        return fd.read().strip()

# Import this for use in cache busting, etc.
__version__ = version_from_file() or "DEV"

Nice, thanks!