fixed issue in python precommit

contributor-docs/python-tips.md

@@ -265,7 +265,17 @@ Execute the following code for running tests using tox:
 
 ### Running Tests Using gradle
 
-Integration tests suites on Jenkins are configured in groovy files that launch certain gradle tasks ([example](https://github.com/apache/beam/blob/0fd6a044df5b9f26d567e0f9a619a665a0f4043b/.test-infra/jenkins/job_PostCommit_Python.groovy#L43)). You could launch test suites locally by executing the gradle targets directly (for example: `./gradlew :sdks:python:test-suites:dataflow:py39:postCommitPy39`). This option may only be available to committers, as by default the test suites are configured to use the [`apache-beam-testing`](https://github.com/apache/beam/blob/0fd6a044df5b9f26d567e0f9a619a665a0f4043b/sdks/python/scripts/run_integration_test.sh#L70) project.
+Integration tests suites on Jenkins are configured in groovy files that launch certain gradle tasks ([example](https://github.com/apache/beam/blob/0fd6a044df5b9f26d567e0f9a619a665a0f4043b/.test-infra/jenkins/job_PostCommit_Python.groovy#L43)). You could launch test suites locally by executing the gradle targets directly (for example: `./gradlew :sdks:python:test-suites:dataflow:py39:postCommitPy39`). This option may only be available to committers, as by default the test suites are configured to use the [`apache-beam-testing`](https://github.com/apache/beam/blob/0fd6a044df5b9f26d567e0f9a619a665a0f4043b/sdks/python/scripts/run_integration_test.sh#L70) project.
+
+### Environment Variables for Test Stability
+
+The following environment variables can be used to improve test stability in CI environments:
+
+**Test execution settings:**
+- `PYTEST_XDIST_WORKER_COUNT=1` - Force sequential test execution
+- `PYTHONHASHSEED=0` - Ensure deterministic hash behavior
+- `OMP_NUM_THREADS=1` - Limit OpenMP threads
+- `OPENBLAS_NUM_THREADS=1` - Limit OpenBLAS threads
 
 To run only a subset of tests using this approach, you could adjust the test label in the test (such as [it_postcommit](https://github.com/apache/beam/blob/25e6008e8919c2f31eaebae2662b44e02f9f37a1/sdks/python/apache_beam/io/gcp/pubsub_integration_test.py#L211)) and the [selector](https://github.com/apache/beam/blob/25e6008e8919c2f31eaebae2662b44e02f9f37a1/sdks/python/test-suites/dataflow/common.gradle#L117) where the test suite is defined.
 

sdks/python/scripts/run_pytest.sh

@@ -152,4 +152,4 @@ if [[ $status1 != 0 && $status1 != 5 ]]; then
 fi
 if [[ $status2 != 0 && $status2 != 5 ]]; then
   exit $status2
-fi
+fi

sdks/python/test-suites/tox/common.gradle

@@ -34,10 +34,9 @@ test.dependsOn "testPy${pythonVersionSuffix}Dill"
 
 // toxTask "testPy${pythonVersionSuffix}Dask", "py${pythonVersionSuffix}-dask", "${posargs}"
 // test.dependsOn "testPy${pythonVersionSuffix}Dask"
+// Since codecoverage reports will always be generated for py39,
+// all tests will be exercised.
 project.tasks.register("preCommitPy${pythonVersionSuffix}") {
-		// Since codecoverage reports will always be generated for py39,
-		// all tests will be exercised.
-		// dependsOn = ["testPy${pythonVersionSuffix}Cloud", "testPython${pythonVersionSuffix}"]
 		dependsOn = ["testPy${pythonVersionSuffix}Cloud", "testPython${pythonVersionSuffix}"]
 
 }