pump.py: add support for Python 3

googlemock/scripts/pump.py

-#!/usr/bin/env python2.7
+#!/usr/bin/env python
 #
 # Copyright 2008, Google Inc.
 # All rights reserved.
@@ -64,6 +64,7 @@ GRAMMAR:
 
 from __future__ import print_function
 
+import io
 import os
 import re
 import sys
@@ -834,7 +835,7 @@ def main(argv):
     sys.exit(1)
 
   file_path = argv[-1]
-  output_str = ConvertFromPumpSource(file(file_path, 'r').read())
+  output_str = ConvertFromPumpSource(io.open(file_path, 'r').read())
   if file_path.endswith('.pump'):
     output_file_path = file_path[:-5]
   else:
@@ -842,11 +843,11 @@ def main(argv):
   if output_file_path == '-':
     print(output_str,)
   else:
-    output_file = file(output_file_path, 'w')
-    output_file.write('// This file was GENERATED by command:\n')
-    output_file.write('//     %s %s\n' %
+    output_file = io.open(output_file_path, 'w')
+    output_file.write(u'// This file was GENERATED by command:\n')
+    output_file.write(u'//     %s %s\n' %
                       (os.path.basename(__file__), os.path.basename(file_path)))
-    output_file.write('// DO NOT EDIT BY HAND!!!\n\n')
+    output_file.write(u'// DO NOT EDIT BY HAND!!!\n\n')
     output_file.write(output_str)
     output_file.close()