code: def version():
      
      global _version
      if _version:
          return _version
      init_file = read_file(MODULE_NAME, '__init__.py')
      matches = re.search(
          r'^__version__\s*=\s*[\'"]([^\'"]*)[\'"]', init_file, re.M)
      if not matches:
          raise RuntimeError("Unable to find version string in __init__.py .")
      _version = matches.group(1)  # noqa
      return _version
docs: Extracts version from the ``__init__.py`` file at the module's root.
  
      Inspired by: https://packaging.python.org/single_source_version/