new module for simple language code to name mapping

test/test_iso639_1.py

@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+# Copyright 2015 Mike Fährmann
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+
+import unittest
+import gallery_dl.iso639_1 as iso639_1
+
+class TestISO639_1(unittest.TestCase):
+
+    def test_code_to_language(self):
+        self.assertEqual(iso639_1.code_to_language("en"), "English")
+        self.assertEqual(iso639_1.code_to_language("xx"), "English")
+        self.assertEqual(iso639_1.code_to_language("xx", default=None), None)
+    def test_language_to_code(self):
+        self.assertEqual(iso639_1.language_to_code("English"), "en")
+        self.assertEqual(iso639_1.language_to_code("Nothing"), "en")
+        self.assertEqual(iso639_1.language_to_code("Nothing", default=None), None)
+
+if __name__ == '__main__':
+    unittest.main()