Fix some file format tests for Python 3

Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/trans/formats.py

@@ -873,7 +873,7 @@ class PoFormat(FileFormat):
     @classmethod
     def create_new_file(cls, filename, code, base):
         """Handles creation of new translation file."""
-        with open(base, 'r') as handle:
+        with open(base, 'rb') as handle:
             data = handle.read()
         # Assume input is UTF-8 if not specified
         if b'Content-Type: text/plain; charset=CHARSET' in data:

weblate/trans/tests/test_formats.py

@@ -22,6 +22,7 @@ File format specific behavior.
 '''
 from __future__ import unicode_literals
 
+import io
 import tempfile
 from unittest import TestCase, SkipTest
 
@@ -116,7 +117,10 @@ class AutoFormatTest(SimpleTestCase):
             testdata = handle.read()
 
         # Create test file
-        testfile = tempfile.NamedTemporaryFile(suffix='.{0}'.format(self.EXT))
+        testfile = tempfile.NamedTemporaryFile(
+            suffix='.{0}'.format(self.EXT),
+            mode='w+'
+        )
         try:
             # Write test data to file
             testfile.write(testdata)
@@ -157,7 +161,10 @@ class AutoFormatTest(SimpleTestCase):
     def test_add(self):
         if self.FORMAT.supports_new_language():
             self.assertTrue(self.FORMAT.is_valid_base_for_new(self.BASE))
-            out = tempfile.NamedTemporaryFile(suffix='.{0}'.format(self.EXT))
+            out = tempfile.NamedTemporaryFile(
+                suffix='.{0}'.format(self.EXT),
+                mode='w+'
+            )
             self.FORMAT.add_language(out.name, 'cs', self.BASE)
             data = out.read()
             self.assertTrue(self.MATCH in data)
@@ -314,9 +321,9 @@ class OutputTest(TestCase):
         out.write(json_input.encode('utf-8'))
         out.flush()
         JSONFormat(out.name).save()
-        with open(out.name) as handle:
+        with io.open(out.name) as handle:
             self.assertEqual(
-                handle.read().decode('UTF-8'),
+                handle.read(),
                 json_expected_output
             )
         out.close()