Hi Dian, As you said, users can, but I got the impression that using ._func to access the original Python function is not recommended, therefore not documented. While in Flink, unit testing a Scala/Java UDF is clearly documented and encouraged.
Do I misread something? Best, Yik San On Wed, Mar 24, 2021 at 10:21 AM Dian Fu <dian0511...@gmail.com> wrote: > As I replied in previous email, it doesn’t block users to write tests for > PyFlink UDFs. Users could use ._func to access the original Python function > if they want. > > Regards, > Dian > > 2021年3月23日 下午2:39，Yik San Chan <evan.chanyik...@gmail.com> 写道： > > Hi Dian, > > However users do want to unit test their UDFs, as supported in > https://ci.apache.org/projects/flink/flink-docs-stable/dev/stream/testing.html#testing-user-defined-functions > > Even though the examples are for Flink, I believe PyFlink should ideally > be no difference. > > What do you think? > > Best, > Yik San > > On Tue, Mar 23, 2021 at 2:19 PM Dian Fu <dian0511...@gmail.com> wrote: > >> Hi Yik San, >> >> This field isn't expected to be exposed to users and so I'm not convinced >> that we should add such an interface/method in Flink. >> >> Regards, >> Dian >> >> On Tue, Mar 23, 2021 at 2:04 PM Yik San Chan <evan.chanyik...@gmail.com> >> wrote: >> >>> Hi Dian, >>> >>> The ._func method seems to be internal only. Maybe we can add some >>> public-facing method to make it more intuitive for use in unit test? >>> What do you think? >>> >>> Best, >>> Yik San >>> >>> On Tue, Mar 23, 2021 at 2:02 PM Yik San Chan <evan.chanyik...@gmail.com> >>> wrote: >>> >>>> Hi Dian, >>>> >>>> Thanks! It solves my problem. >>>> >>>> Best, >>>> Yik San >>>> >>>> On Tue, Mar 23, 2021 at 1:29 PM Dian Fu <dian0511...@gmail.com> wrote: >>>> >>>>> H Yik San, >>>>> >>>>> As the udf `add` is decorated with `@udf` decorator, it is no longer a >>>>> simple Python function if you reference `add`. If you execute >>>>> `print(type(add(1, 1)))`, you will see the output is something like >>>>> "<class >>>>> 'pyflink.table.expression.Expression'>". >>>>> >>>>> You could try the following code: assert add._func(1, 1) == 3 >>>>> >>>>> add._func returns the original Python function. >>>>> >>>>> Regards, >>>>> Dian >>>>> >>>>> On Tue, Mar 23, 2021 at 10:56 AM Yik San Chan < >>>>> evan.chanyik...@gmail.com> wrote: >>>>> >>>>>> (This question is cross-posted on StackOverflow >>>>>> https://stackoverflow.com/questions/66756612/failed-to-unit-test-pyflink-udf >>>>>> ) >>>>>> >>>>>> I am using PyFlink and I want to unit test my UDF written in Python. >>>>>> >>>>>> To test the simple udf below: >>>>>> >>>>>> ```python >>>>>> # tasks/helloworld/udf.py >>>>>> from pyflink.table import DataTypes >>>>>> from pyflink.table.udf import udf >>>>>> >>>>>> @udf(input_types=[DataTypes.INT(), DataTypes.INT()], >>>>>> result_type=DataTypes.BIGINT()) >>>>>> def add(i, j): >>>>>> return i + j >>>>>> ``` >>>>>> >>>>>> I create a test file that should fail: >>>>>> ```python >>>>>> from tasks.helloworld.udf import add >>>>>> >>>>>> def test_add(): >>>>>> assert add(1,1) == 3 >>>>>> ``` >>>>>> >>>>>> Sadly, it passes if I run `pytest`: >>>>>> ``` >>>>>> > pytest >>>>>> =========================================================================================== >>>>>> test session starts >>>>>> ============================================================================================ >>>>>> platform darwin -- Python 3.7.10, pytest-6.2.2, py-1.10.0, >>>>>> pluggy-0.13.1 >>>>>> rootdir: /Users/chenyisheng/source/yiksanchan/pytest-flink >>>>>> collected 1 item >>>>>> >>>>>> tests/test_helloworld.py . >>>>>> >>>>>> [100%] >>>>>> >>>>>> ============================================================================================= >>>>>> warnings summary >>>>>> ============================================================================================= >>>>>> >>>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>>> >>>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>>> >>>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>>> >>>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>>> >>>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>>> >>>>>> /usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13: >>>>>> DeprecationWarning: Using or importing the ABCs from 'collections' >>>>>> instead >>>>>> of from 'collections.abc' is deprecated since Python 3.3,and in 3.9 it >>>>>> will >>>>>> stop working >>>>>> from collections import ( >>>>>> >>>>>> >>>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/pyflink/table/udf.py:291 >>>>>> >>>>>> /usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/pyflink/table/udf.py:291: >>>>>> DeprecationWarning: Using or importing the ABCs from 'collections' >>>>>> instead >>>>>> of from 'collections.abc' is deprecated since Python 3.3,and in 3.9 it >>>>>> will >>>>>> stop working >>>>>> if not isinstance(input_types, collections.Iterable) \ >>>>>> >>>>>> -- Docs: https://docs.pytest.org/en/stable/warnings.html >>>>>> ====================================================================================== >>>>>> 1 passed, 6 warnings in 0.98s >>>>>> ======================================================================================= >>>>>> ``` >>>>>> >>>>>> However, the test will fail as expected if I remove the >>>>>> `@udf(input_types=[...], result_type=...)` annotation: >>>>>> ``` >>>>>> > pytest >>>>>> =========================================================================================== >>>>>> test session starts >>>>>> ============================================================================================ >>>>>> platform darwin -- Python 3.7.10, pytest-6.2.2, py-1.10.0, >>>>>> pluggy-0.13.1 >>>>>> rootdir: /Users/chenyisheng/source/yiksanchan/pytest-flink >>>>>> collected 1 item >>>>>> >>>>>> tests/test_helloworld.py F >>>>>> >>>>>> [100%] >>>>>> >>>>>> ================================================================================================= >>>>>> FAILURES >>>>>> ================================================================================================= >>>>>> _________________________________________________________________________________________________ >>>>>> test_add >>>>>> _________________________________________________________________________________________________ >>>>>> >>>>>> def test_add(): >>>>>> > assert add(1,1) == 3 >>>>>> E assert 2 == 3 >>>>>> E + where 2 = add(1, 1) >>>>>> >>>>>> tests/test_helloworld.py:4: AssertionError >>>>>> ============================================================================================= >>>>>> warnings summary >>>>>> ============================================================================================= >>>>>> >>>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>>> >>>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>>> >>>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>>> >>>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>>> >>>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>>> >>>>>> /usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13: >>>>>> DeprecationWarning: Using or importing the ABCs from 'collections' >>>>>> instead >>>>>> of from 'collections.abc' is deprecated since Python 3.3,and in 3.9 it >>>>>> will >>>>>> stop working >>>>>> from collections import ( >>>>>> >>>>>> -- Docs: https://docs.pytest.org/en/stable/warnings.html >>>>>> ========================================================================================= >>>>>> short test summary info >>>>>> ========================================================================================== >>>>>> FAILED tests/test_helloworld.py::test_add - assert 2 == 3 >>>>>> ====================================================================================== >>>>>> 1 failed, 5 warnings in 0.17s >>>>>> ======================================================================================= >>>>>> ``` >>>>>> >>>>>> The full example can be found >>>>>> https://github.com/YikSanChan/how-to-pytest-flink. >>>>>> >>>>>> Best, >>>>>> Yik San >>>>>> >>>>> >
