Missing introspection methods in Python

src/ifcopenshell-python/ifcopenshell/entity_instance.py

@@ -120,8 +120,8 @@ class entity_instance(object):
     def __dir__(self):
         return sorted(set(itertools.chain(
             dir(type(self)),
-            self.wrapped_data.get_attribute_names(),
-            self.wrapped_data.get_inverse_attribute_names()
+            map(str, self.wrapped_data.get_attribute_names()),
+            map(str, self.wrapped_data.get_inverse_attribute_names())
         )))
 
     def get_info(self, include_identifier=True, recursive=False):

src/ifcwrap/IfcParseWrapper.i

@@ -109,9 +109,26 @@ private:
 
 	// id() is defined on IfcBaseEntity and not on IfcBaseClass, in order
 	// to expose it to the Python wrapper it is simply duplicated here.
+	// Same applies to the two methods reimplemented below.
 	int id() const {
 		return $self->entity->id();
 	}
+
+	std::vector<std::string> getAttributeNames() const {
+		if (IfcSchema::Type::IsSimple($self->type())) {
+			return std::vector<std::string>(1, "wrappedValue");
+		}
+		IfcUtil::IfcBaseEntity* self_ = (IfcUtil::IfcBaseEntity*) self; 
+		return self_->getAttributeNames();
+	}
+
+	std::vector<std::string> getInverseAttributeNames() const {
+		if (IfcSchema::Type::IsSimple($self->type())) {
+			return std::vector<std::string>(0);
+		}
+		IfcUtil::IfcBaseEntity* self_ = (IfcUtil::IfcBaseEntity*) self; 
+		return self_->getInverseAttributeNames();
+	}
 	
 	bool is_a(const std::string& s) {
 		return self->is(IfcSchema::Type::FromString(boost::to_upper_copy(s)));