### Discussed in https://github.com/apache/airflow/discussions/33345

<div type='discussions-op-text'>

<sup>Originally posted by **vuphamcs** August 11, 2023</sup>
### Description

Is there a variable similar to `prev_start_date_success` but for the previous DAG run’s completion date? The value I’m hoping to retrieve to use within the next DAG run is `2023-08-10 16:04:30`

![image](https://github.com/apache/airflow/assets/1600760/9e2af349-4c3e-47e1-8a1a-9d8827b56f57)


### Use case/motivation

One particular use case is to help guarantee that the next DAG run only queries data that was inserted during the existing DAG run, and not the past DAG run.

```python
prev_ts = context['prev_end_date_success']

sql = f"SELECT * FROM results WHERE created_at > {context['prev_end_date_success']}"
```

### Related issues

_No response_

### Are you willing to submit a PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)
</div>
self.run = False
    def do_run(self):
        self.run = True
    def is_run(self):
        return self.run
    def test_python_operator_run(self):
        """Tests that the python callable is invoked on task run."""
        ti = self.create_ti(self.do_run)
        assert not self.is_run()
        ti.run()
        assert self.is_run()
    @pytest.mark.parametrize("not_callable", [{}, None])
    def test_python_operator_python_callable_is_callable(self, not_callable):
        """Tests that PythonOperator will only instantiate if the python_callable argument is callable."""
        with pytest.raises(AirflowException, match="`python_callable` param must be callable"):
            PythonOperator(python_callable=not_callable, task_id="python_operator")
    def test_python_callable_arguments_are_templatized(self):
        """Test PythonOperator op_args are templatized"""
        
        
        Named = namedtuple("Named", ["var1", "var2"])
        named_tuple = Named("{{ ds }}", "unchanged")
        task = self.render_templates(
            lambda: 0,
            op_args=[4, date(2019, 1, 1), "dag {{dag.dag_id}} ran on {{ds}}.", named_tuple],
        )
        rendered_op_args = task.op_args
        assert len(rendered_op_args) == 4
        assert rendered_op_args[0] == 4
        assert rendered_op_args[1] == date(2019, 1, 1)