Added support for default values to load_component (kubeflow#889)

sdk/python/kfp/components/_components.py

@@ -200,7 +200,7 @@ def create_task_from_component_and_arguments(pythonic_arguments):
 
     #Reordering the inputs since in Python optional parameters must come after reuired parameters
     reordered_input_list = [input for input in inputs_list if not input.optional] + [input for input in inputs_list if input.optional]
-    input_parameters  = [_dynamic.KwParameter(input_name_to_pythonic[port.name], annotation=(_try_get_object_by_name(str(port.type)) if port.type else inspect.Parameter.empty), default=(None if port.optional else inspect.Parameter.empty)) for port in reordered_input_list]
+    input_parameters  = [_dynamic.KwParameter(input_name_to_pythonic[port.name], annotation=(_try_get_object_by_name(str(port.type)) if port.type else inspect.Parameter.empty), default=port.default if port.default is not None else (None if port.optional else inspect.Parameter.empty)) for port in reordered_input_list]
     factory_function_parameters = input_parameters #Outputs are no longer part of the task factory function signature. The paths are always generated by the system.
 
     return _dynamic.create_function_from_parameters(

sdk/python/tests/components/test_components.py

@@ -476,6 +476,24 @@ def test_handling_env(self):
         expected_env = {'key1': 'value 1', 'key2': 'value 2'}
         self.assertDictEqual(expected_env, actual_env)
 
+    def test_handle_default_values_in_task_factory(self):
+        component_text = '''\
+inputs:
+- {name: Data, default: '123'}
+implementation:
+  container:
+    image: busybox
+    args:
+      - {inputValue: Data}
+'''
+        task_factory1 = comp.load_component_from_text(text=component_text)
+
+        task1 = task_factory1()
+        self.assertEqual(task1.arguments, ['123'])
+
+        task2 = task_factory1('456')
+        self.assertEqual(task2.arguments, ['456'])
+
 
 if __name__ == '__main__':
     unittest.main()