add

gokart/task.py

@@ -16,6 +16,7 @@
 from gokart.parameter import ExplicitBoolParameter, ListTaskInstanceParameter, TaskInstanceParameter
 from gokart.redis_lock import make_redis_params
 from gokart.target import TargetOnKart
+from gokart.task_complete_check import task_complete_check_wrapper
 
 logger = getLogger(__name__)
 
@@ -76,6 +77,8 @@ class TaskOnKart(luigi.Task):
         description='Whether to dump supplementary files (task_log, random_seed, task_params, processing_time, module_versions) or not. \
          Note that when set to False, task_info functions (e.g. gokart.tree.task_info.make_task_info_as_tree_str()) cannot be used.',
         significant=False)
+    complete_check_at_run: bool = ExplicitBoolParameter(
+        default=False, description='Check if output file exists at run. If exists, run() will be skipped.', significant=False)
 
     def __init__(self, *args, **kwargs):
         self._add_configuration(kwargs, 'TaskOnKart')
@@ -86,6 +89,9 @@ def __init__(self, *args, **kwargs):
         self._rerun_state = self.rerun
         self._lock_at_dump = True
 
+        if self.complete_check_at_run:
+            self.run = task_complete_check_wrapper(run_func=self.run, complete_check_func=self.complete)
+
     def output(self):
         return self.make_target()
 

gokart/task_complete_check.py

@@ -0,0 +1,9 @@
+from typing import Callable
+
+
+def task_complete_check_wrapper(run_func: Callable, complete_check_func: Callable):
+    def wrapper(*args, **kwargs):
+        if not complete_check_func():
+            run_func(*args, **kwargs)
+
+    return wrapper

test/test_task_on_kart.py

@@ -561,5 +561,65 @@ def test_serialize_and_deserialize_default_values(self):
         self.assertDictEqual(task.to_str_params(), deserialized.to_str_params())
 
 
+class _DummyTaskWithNonCompleted(gokart.TaskOnKart):
+
+    def dump(self, obj):
+        # overrive dump() to do nothing.
+        pass
+
+    def run(self):
+        self.dump('hello')
+
+    def complete(self):
+        return False
+
+
+class _DummyTaskWithCompleted(gokart.TaskOnKart):
+
+    def dump(self, obj):
+        # overrive dump() to do nothing.
+        pass
+
+    def run(self):
+        self.dump('hello')
+
+    def complete(self):
+        return True
+
+
+class TestCompleteCheckAtRun(unittest.TestCase):
+    def test_run_when_complete_check_at_run_is_false_and_task_is_not_completed(self):
+        task = _DummyTaskWithNonCompleted(complete_check_at_run=False)
+        task.dump = MagicMock()
+        task.run()
+
+        # since run() is called, dump() should be called.
+        task.dump.assert_called_once()
+
+    def test_run_when_complete_check_at_run_is_false_and_task_is_completed(self):
+        task = _DummyTaskWithCompleted(complete_check_at_run=False)
+        task.dump = MagicMock()
+        task.run()
+
+        # even task is completed, since run() is called, dump() should be called.
+        task.dump.assert_called_once()
+
+    def test_run_when_complete_check_at_run_is_true_and_task_is_not_completed(self):
+        task = _DummyTaskWithNonCompleted(complete_check_at_run=True)
+        task.dump = MagicMock()
+        task.run()
+
+        # since task is not completed, when run() is called, dump() should be called.
+        task.dump.assert_called_once()
+
+    def test_run_when_complete_check_at_run_is_true_and_task_is_completed(self):
+        task = _DummyTaskWithCompleted(complete_check_at_run=True)
+        task.dump = MagicMock()
+        task.run()
+
+        # since task is completed, even when run() is called, dump() should not be called.
+        task.dump.assert_not_called()
+
+
 if __name__ == '__main__':
     unittest.main()