[python] Add ut cover process definitions separate mode (#6908)

* [python] Add ut cover process definitions separate mode

* Remove unused print syntax

* Fix test error, cause raw_script not exists anymore

dolphinscheduler-python/pydolphinscheduler/tests/core/test_process_definition.py

@@ -170,8 +170,8 @@ def test_process_definition_to_dict_without_task():
         assert pd.to_dict() == expect
 
 
-def test_process_definition_simple():
-    """Test process definition simple create workflow, including process definition, task, relation define."""
+def test_process_definition_simple_context_manager():
+    """Test simple create workflow in process definition context manager mode."""
     expect_tasks_num = 5
     with ProcessDefinition(TEST_PROCESS_DEFINITION_NAME) as pd:
         for i in range(expect_tasks_num):
@@ -211,6 +211,30 @@ def test_process_definition_simple():
                 }
 
 
+def test_process_definition_simple_separate():
+    """Test process definition simple create workflow in separate mode.
+
+    This test just test basic information, cause most of test case is duplicate to
+    test_process_definition_simple_context_manager.
+    """
+    expect_tasks_num = 5
+    pd = ProcessDefinition(TEST_PROCESS_DEFINITION_NAME)
+    for i in range(expect_tasks_num):
+        task_params = TaskParams()
+        curr_task = Task(
+            name=f"task-{i}",
+            task_type=f"type-{i}",
+            task_params=task_params,
+            process_definition=pd,
+        )
+        # Set deps task i as i-1 parent
+        if i > 0:
+            pre_task = pd.get_one_task_by_name(f"task-{i - 1}")
+            curr_task.set_upstream(pre_task)
+    assert len(pd.tasks) == expect_tasks_num
+    assert all(["task-" in task.name for task in pd.task_list])
+
+
 @pytest.mark.parametrize(
     "user_attrs",
     [