Python: automagically increment version with commit count

setup.py

import setuptools
import subprocess

major_version = '1.4'
commits = commits = subprocess.check_output(
    ['/usr/bin/git', 'rev-list', 'HEAD', '--count']).decode('utf8').strip()

kwargs = {}  # you know what to put here

setuptools.setup(
  version='{}.{}'.format(major_version, commits),
  **kwargs)