Add future imports

escpos/cli.py

@@ -9,6 +9,9 @@ It requires you to have a configuration file. See documentation for details.
 """
 
 from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
 
 import argparse
 import sys

escpos/config.py

@@ -5,6 +5,9 @@ This module contains the implentations of abstract base class :py:class:`Config`
 """
 
 from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
 
 import os
 import appdirs