code: def find_root_path(absolute_path, relative_path):
      
      _absolute_path = os.path.normpath(absolute_path)
      _relative_path = os.path.normpath(relative_path)
  
      index = _absolute_path.rfind(_relative_path)
      if index == -1 or len(_relative_path) + index < len(_absolute_path):
          raise ValueError('The relative path does not end the specified absolute path')
  
      return _absolute_path[:index]
docs: Return the root path of a path relative to an absolute path.
  
      Example:
  
      @param absolute_path: an absolute path that is ended by the specified
          relative path.
  
      @param relative_path: a relative path that ends the specified absolute
          path.
  
      @return: the root path of the relative path.