Merge pull request #2002 from jerneju/metadata-save

[FIX] data/io.py Metadata file not saved anymore when it is empty

Author: astaric

Orange/data/io.py

@@ -373,7 +373,7 @@ def write(cls, filename, data):
 
     @classmethod
     def write_table_metadata(cls, filename, data):
-        if isinstance(filename, str) and hasattr(data, 'attributes'):
+        if isinstance(filename, str) and getattr(data, 'attributes', None):
             if all(isinstance(key, str) and isinstance(value, str)
                    for key, value in data.attributes.items()):
                 with open(filename + '.metadata', 'w') as f:

Orange/tests/test_tab_reader.py

@@ -206,3 +206,23 @@ def test_data_name(self):
         table2 = TabReader(table1.__file__).read()
         self.assertEqual(table1.name, 'iris')
         self.assertEqual(table2.name, 'iris')
+
+    def test_metadata(self):
+        tempdir = tempfile.mkdtemp()
+        table = Table("titanic")
+        table.attributes = OrderedDict()
+        table.attributes["a"] = "aa"
+        table.attributes["b"] = "bb"
+        fname = path.join(tempdir, "out.tab")
+        TabReader.write_table_metadata(fname, table)
+        self.assertTrue(path.isfile(fname + ".metadata"))
+        shutil.rmtree(tempdir)
+
+    def test_no_metadata(self):
+        tempdir = tempfile.mkdtemp()
+        table = Table("titanic")
+        table.attributes = OrderedDict()
+        fname = path.join(tempdir, "out.tab")
+        TabReader.write_table_metadata(fname, table)
+        self.assertFalse(path.isfile(fname + ".metadata"))
+        shutil.rmtree(tempdir)