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Posted to commits@airflow.apache.org by GitBox <gi...@apache.org> on 2021/11/11 17:01:53 UTC

[GitHub] [airflow] josh-fell opened a new issue #19538: TaskFlow API `multiple_outputs` inference not handling all flavors of dict typing

josh-fell opened a new issue #19538:
URL: https://github.com/apache/airflow/issues/19538


   ### Apache Airflow version
   
   2.2.0
   
   ### Operating System
   
   Debian GNU/Linux 11 (bullseye)
   
   ### Versions of Apache Airflow Providers
   
   ```shell
   apache-airflow-providers-amazon          1!2.2.0
   apache-airflow-providers-cncf-kubernetes 1!2.0.3
   apache-airflow-providers-elasticsearch   1!2.0.3
   apache-airflow-providers-ftp             1!2.0.1
   apache-airflow-providers-google          1!6.0.0
   apache-airflow-providers-http            1!2.0.1
   apache-airflow-providers-imap            1!2.0.1
   apache-airflow-providers-microsoft-azure 1!3.2.0
   apache-airflow-providers-mysql           1!2.1.1
   apache-airflow-providers-postgres        1!2.3.0
   apache-airflow-providers-redis           1!2.0.1
   apache-airflow-providers-slack           1!4.1.0
   apache-airflow-providers-sqlite          1!2.0.1
   apache-airflow-providers-ssh             1!2.2.0
   ```
   
   ### Deployment
   
   Astronomer
   
   ### Deployment details
   
   Local deployment using the Astronomer CLI.
   
   ### What happened
   
   Creating a TaskFlow function with a return type annotation of `dict` does not yield `XComs` for each key within the returned dict.  Additionally, the inference does not work for both `dict` and `Dict` (without arg annotation) types in Python 3.6.
   
   ### What you expected to happen
   
   When creating a TaskFlow function and not explicitly setting `multiple_outputs=True`, the unfurling of `XComs` into separate keys is inferred by the return type annotation (as noted [here](https://airflow.apache.org/docs/apache-airflow/stable/tutorial_taskflow_api.html#multiple-outputs-inference)). When using a return type annotation of `dict`, separate `XComs` should be created. There is an explicit check for this type as well:
   
   https://github.com/apache/airflow/blob/7622f5e08261afe5ab50a08a6ca0804af8c7c7fe/airflow/decorators/base.py#L207
   
   Additionally, on Python 3.6, the inference should handle generating multiple `XComs` for both `dict` and `typing.Dict` return type annotations as expected on other Python versions.
   
   ### How to reproduce
   
   This DAG can be used to demonstrate the different results of dict typing:
   ```python
   from datetime import datetime
   from typing import Dict
   
   from airflow.decorators import dag, task
   from airflow.models.baseoperator import chain
   from airflow.models import XCom
   
   
   @dag(
       start_date=datetime(2021, 11, 11),
       schedule_interval=None,
   )
   def __test__():
       @task
       def func_no_return_anno():
           return {"key1": "value1", "key2": "value2"}
   
       @task
       def func_with_dict() -> dict:
           return {"key1": "value1", "key2": "value2"}
   
       @task
       def func_with_typing_dict() -> Dict:
           return {"key1": "value1", "key2": "value2"}
   
       @task
       def func_with_typing_dict_explicit() -> Dict[str, str]:
           return {"key1": "value1", "key2": "value2"}
   
       @task
       def get_xcoms(run_id=None):
           xcoms = XCom.get_many(
               dag_ids="__test__",
               task_ids=[
                   "func_no",
                   "func_with_dict",
                   "func_with_typing_dict",
                   "func_with_typing_dict_explicit",
               ],
               run_id=run_id,
           ).all()
   
           for xcom in xcoms:
               print(f"Task ID: {xcom.task_id} \n", f"Key: {xcom.key} \n", f"Value: {xcom.value}")
   
       chain(
           [
               func_no_return_anno(),
               func_with_dict(),
               func_with_typing_dict(),
               func_with_typing_dict_explicit(),
           ],
           get_xcoms(),
       )
   
   
   dag = __test__()
   
   ```
   
   **Expected `XCom` keys**
   - func_no_return_anno
     - `return_value`
   - func_with_dict
     - `return_value`, `key1`, and `key2`
   - func_with_typing_dict
     - `return_value`, `key1`, and `key2`
   - func_with_typing_dict_explicit
     - `return_value`, `key1`, and `key2`
   
   Here is the output from the `get_xcoms` task which is gathering all of the `XComs` generated for the run:
   ![image](https://user-images.githubusercontent.com/48934154/141336206-259bd78b-8ef3-4edb-81a6-b161d783f39f.png)
   
   The `func_with_dict` task does not yield `XComs` for `key1` and `key2`.
   
   ### Anything else
   
   The inference also doesn't function as intended on Python 3.6 when using simple `dict` or `Dict` return types.
   
   For example, isolating the existing `TestAirflowTaskDecorator::test_infer_multiple_outputs_using_typing` unit test and adding some parameterization on Python 3.6:
   ```python
   @parameterized.expand(
           [
               ("dict", dict),
               ("Dict", Dict),
               ("Dict[str, int]", Dict[str, int]),
           ]
       )
       def test_infer_multiple_outputs_using_typing(self, _, test_return_annotation):
           @task_decorator
           def identity_dict(x: int, y: int) -> test_return_annotation:
               return {"x": x, "y": y}
   
           assert identity_dict(5, 5).operator.multiple_outputs is True
   ```
   **Results**
   ![image](https://user-images.githubusercontent.com/48934154/141338408-5d7f2877-6465-4c81-857f-5ca6d1b612ee.png)
   
   
   However, since Python 3.6 will reach EOL on 2021-12-23, this _may_ not be an aspect that needs to be fixed.
   
   ### Are you willing to submit PR?
   
   - [X] 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)
   


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[GitHub] [airflow] yiga2 commented on issue #19538: TaskFlow API `multiple_outputs` inference not handling all flavors of dict typing

Posted by GitBox <gi...@apache.org>.
yiga2 commented on issue #19538:
URL: https://github.com/apache/airflow/issues/19538#issuecomment-970476479


   Probably a different issue or a feature request but can `multiple_outputs` not be available on any (all?) operators that could return a `dict` e.g. pseudo-code
   ```
   if isinstance(returned_value, dict) and multiple_ouputs:
       # unroll and xcom_push each key 
   
   ```
   x-post: https://apache-airflow.slack.com/archives/CCPRP7943/p1637081028345300


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[GitHub] [airflow] potiuk closed issue #19538: TaskFlow API `multiple_outputs` inference not handling all flavors of dict typing

Posted by GitBox <gi...@apache.org>.
potiuk closed issue #19538:
URL: https://github.com/apache/airflow/issues/19538


   


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