Parameters: fix Parameter inheritance when setting attributes

psyneulink/core/globals/parameters.py

@@ -572,7 +572,6 @@ def __getattr__(self, attr):
     def __setattr__(self, attr, value):
         if (attr[:1] != '_'):
             param = getattr(self._owner.parameters, attr)
-            param._inherited = False
             param.default_value = value
         else:
             super().__setattr__(attr, value)
@@ -927,6 +926,7 @@ def __init__(
             _inherited=_inherited,
             _inherited_source=_inherited_source,
             _user_specified=_user_specified,
+            _temp_uninherited=set(),
             **kwargs
         )
 
@@ -1011,10 +1011,15 @@ def __getattr__(self, attr):
 
     def __setattr__(self, attr, value):
         if attr in self._additional_param_attr_properties:
+            self._temp_uninherited.add(attr)
+            self._inherited = False
+
             try:
                 getattr(self, '_set_{0}'.format(attr))(value)
             except AttributeError:
                 super().__setattr__(attr, value)
+
+            self._temp_uninherited.remove(attr)
         else:
             super().__setattr__(attr, value)
 
@@ -1053,6 +1058,7 @@ def _inherited(self, value):
         if value is not self._inherited:
             # invalid if set to inherited
             self._is_invalid_source = value
+            self.__inherited = value
 
             if value:
                 self._cache_inherited_attrs()
@@ -1078,14 +1084,14 @@ def _inherited(self, value):
 
                 self._restore_inherited_attrs()
 
-            self.__inherited = value
-
     def _inherit_from(self, parent):
         self._inherited_source = weakref.ref(parent)
 
     def _cache_inherited_attrs(self, exclusions=None):
         if exclusions is None:
-            exclusions = self._uninherited_attrs
+            exclusions = set()
+
+        exclusions = self._uninherited_attrs.union(self._temp_uninherited).union(exclusions)
 
         for attr in self._param_attrs:
             if attr not in exclusions:
@@ -1094,7 +1100,9 @@ def _cache_inherited_attrs(self, exclusions=None):
 
     def _restore_inherited_attrs(self, exclusions=None):
         if exclusions is None:
-            exclusions = self._uninherited_attrs
+            exclusions = set()
+
+        exclusions = self._uninherited_attrs.union(self._temp_uninherited).union(exclusions)
 
         for attr in self._param_attrs:
             if (
@@ -1786,12 +1794,12 @@ def __setattr__(self, attr, value):
 
     def _cache_inherited_attrs(self):
         super()._cache_inherited_attrs(
-            exclusions=self._uninherited_attrs.union(self._sourced_attrs)
+            exclusions=self._sourced_attrs
         )
 
     def _restore_inherited_attrs(self):
         super()._restore_inherited_attrs(
-            exclusions=self._uninherited_attrs.union(self._sourced_attrs)
+            exclusions=self._sourced_attrs
         )
 
     def _set_name(self, name):

tests/misc/test_parameters.py

@@ -83,6 +83,19 @@ def test_parameter_values_overriding(ancestor, child, should_override, reset_var
         assert child.parameters.variable.default_value == original_child_variable
 
 
+def test_unspecified_inheritance():
+    class NewTM(pnl.TransferMechanism):
+        class Parameters(pnl.TransferMechanism.Parameters):
+            pass
+
+    assert NewTM.parameters.variable._inherited
+    NewTM.parameters.variable.default_value = -1
+    assert not NewTM.parameters.variable._inherited
+
+    NewTM.parameters.variable.reset()
+    assert NewTM.parameters.variable._inherited
+
+
 @pytest.mark.parametrize('obj, param_name, alias_name', param_alias_data)
 def test_aliases(obj, param_name, alias_name):
     obj = obj()