code: def docker_path(filepath, work_dir=None):
      
      if work_dir:
          return re.sub(work_dir, '/data', filepath)
  
      else:
          return os.path.join('/data', os.path.basename(filepath))
docs: Given a path, return that files path inside the docker mount directory (/data).
  
      :param str filepath: The path to a file
      :param str work_dir: The part of the path to replace with /data
      :return: The docker-friendly path for `filepath`
      :rtype: str