text: # -*- coding: utf-8 -*-
  
  """Exceptions for input/output."""
  
  from typing import Tuple
  
  from ..exceptions import PyBELWarning
  
  import_version_message_fmt = 'Tried importing from PyBEL v{}. Need at least v{}'
  
  
  class ImportVersionWarning(PyBELWarning, ValueError):
      """Raised when trying to import data from an old version of PyBEL."""
  
      def __init__(self, actual_version_tuple: Tuple[int, int, int], minimum_version_tuple: Tuple[int, int, int]) -> None:
          """Build an import version warning."""
          super().__init__(actual_version_tuple, minimum_version_tuple)
          self.actual_tuple = actual_version_tuple
          self.minimum_tuple = minimum_version_tuple
  
      def __str__(self):
          actual_s = '.'.join(map(str, self.actual_tuple))
          minimum_s = '.'.join(map(str, self.minimum_tuple))
          return import_version_message_fmt.format(actual_s, minimum_s)
  