Raise UnsupportedFormat for a list with non-uniform row types in _set_dict

src/tablib/core.py

@@ -364,13 +364,22 @@ def _set_dict(self, pickle):
         if isinstance(pickle[0], list):
             self.wipe()
             for row in pickle:
+                # only the first element's type is checked above, so a later
+                # row of a different type (e.g. a null item in a YAML list)
+                # would otherwise raise a bare TypeError.
+                if not isinstance(row, list):
+                    raise UnsupportedFormat(error_details)
                 self.append(Row(row))
 
         # if list of objects
         elif isinstance(pickle[0], dict):
             self.wipe()
             self.headers = list(pickle[0].keys())
             for row in pickle:
+                # guard against a later row that is not a dict, which would
+                # otherwise raise a bare AttributeError from row.values().
+                if not isinstance(row, dict):
+                    raise UnsupportedFormat(error_details)
                 self.append(Row(list(row.values())))
         else:
             raise UnsupportedFormat(error_details)

tests/test_tablib.py

@@ -1801,6 +1801,14 @@ def test_yaml_import_set(self):
 
         self.assertEqual(_yaml, data.yaml)
 
+    def test_yaml_import_set_with_non_dict_row(self):
+        """A YAML list whose first item is a dict but a later item is not
+        (e.g. a trailing bare ``-`` which parses to null) used to raise a bare
+        AttributeError from row.values(); it should raise UnsupportedFormat."""
+        _yaml = '- {id: 0, name: n0}\n- {id: 1, name: n1}\n-\n'
+        with self.assertRaises(UnsupportedFormat):
+            tablib.Dataset().load(_yaml, 'yaml')
+
     def test_yaml_export(self):
         """YAML export"""