if a key is missing, report with a KeyError in AttrDict

src/wxflow/attrdict.py

@@ -81,7 +81,7 @@ def __getattr__(self, item):
     def __missing__(self, name):
         if object.__getattribute__(self, '__frozen'):
             raise KeyError(name)
-        return self.__class__(__parent=self, __key=name)
+        raise KeyError(name)
 
     def __delattr__(self, name):
         del self[name]

tests/test_attrdict.py

@@ -0,0 +1,19 @@
+import pytest
+
+from wxflow import AttrDict
+
+TEST_VAL = [1, 2, 3]
+TEST_DICT = {'a': {'b': {'c': TEST_VAL}}}
+
+
+def test_set_one_level_item():
+    some_dict = {'a': TEST_VAL}
+    prop = AttrDict()
+    prop['a'] = TEST_VAL
+    assert prop == some_dict
+
+
+def test_missing():
+    prop = AttrDict(TEST_DICT)
+    with pytest.raises(KeyError):
+        prop['b']