code: def version(package, encoding='utf-8'):
      
      path = os.path.join(os.path.dirname(__file__), package, '__init__.py')
      with io.open(path, encoding=encoding) as fp:
          version_info = fp.read()
      version_match = re.search(r"""^__version__ = ['"]([^'"]*)['"]""",
                                version_info, re.M)
      if not version_match:
          raise RuntimeError("Unable to find version string.")
      return version_match.group(1)
docs: Obtain the packge version from a python file e.g. pkg/__init__.py
      See <https://packaging.python.org/en/latest/single_source_version.html>.