Fix print for GaussianNormalizer (#905)

Author: fealho

rdt/transformers/base.py

@@ -343,7 +343,7 @@ def __repr__(self):
         instanced = {
             key: getattr(self, key)
             for key in keys
-            if key != 'model_missing_values'  # Remove after deprecation
+            if key != 'model_missing_values' and hasattr(self, key)  # Remove after deprecation
         }
 
         if defaults == instanced:

tests/unit/transformers/test_numerical.py

@@ -1176,6 +1176,18 @@ def test__reverse_transform_missing_value_generation(self):
         # Assert
         np.testing.assert_allclose(transformed_data, expected, rtol=1e-3)
 
+    def test_print(self, capsys):
+        """Test the class can be printed. GH#883"""
+        # Setup
+        transformer = GaussianNormalizer()
+
+        # Run
+        print(transformer)  # noqa: T201 `print` found
+
+        # Assert
+        captured = capsys.readouterr()
+        assert captured.out == 'GaussianNormalizer()\n'
+
 
 class TestClusterBasedNormalizer(TestCase):
     def test__get_current_random_seed_random_states_is_none(self):