fix autogenerated persistent id duplication error (#9482)

GitOrigin-RevId: fc362b90a084d88ac7115e2e9243bb630ec31d57

Author: zxqfd555

CHANGELOG.md

@@ -17,6 +17,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Endpoints created by `pw.io.http.rest_connector` now accept requests both with and without a trailing slash. For example, `/endpoint/` and `/endpoint` are now treated equivalently.
 - Schemas that inherit from other schemas now automatically preserve all properties from their parent schemas.
 - Fixed an issue where the persistence configuration failed when provided with a relative filesystem path.
+- Fixed unique name autogeneration for the Python connectors.
 
 ## [0.26.4] - 2025-10-16
 

python/pathway/tests/test_io.py

@@ -1205,6 +1205,29 @@ def test_duplicated_name(tmp_path: pathlib.Path):
         )
 
 
+def test_duplicated_name_for_python_connector(tmp_path: pathlib.Path):
+    class MySchema(pw.Schema):
+        a: int
+        b: str
+
+    class MySubject(pw.io.python.ConnectorSubject):
+        def run(self) -> None:
+            for i in range(4):
+                self.next(a=i, b=f"x{i}")
+
+        @property
+        def _deletions_enabled(self) -> bool:
+            return False
+
+    t1 = pw.io.python.read(MySubject(), schema=MySchema)
+    t2 = pw.io.python.read(MySubject(), schema=MySchema)
+    pw.io.null.write(t1)
+    pw.io.null.write(t2)
+    persistence_backend = pw.persistence.Backend.filesystem(tmp_path / "PStorage")
+    persistence_config = pw.persistence.Config(persistence_backend)
+    run_all(persistence_config=persistence_config)
+
+
 def test_duplicated_name_between_input_and_output(tmp_path: pathlib.Path):
     pstorage_path = tmp_path / "PStorage"
     input_path = tmp_path / "input_first.txt"

src/engine/dataflow.rs

@@ -3895,7 +3895,7 @@ impl<S: MaybeTotalScope<MaybeTotalTimestamp = Timestamp>> DataflowGraphInner<S>
             unique_name,
             RequiredPersistenceMode::InputOrOperatorPersistence,
             |_| {
-                let generated_external_id = reader.name(None);
+                let generated_external_id = format!("{}-{}", reader.name(None), self.pollers.len());
                 info!(
                     "Unique name autogenerated for a {:?} reader because persistence is enabled: {generated_external_id}",
                     reader.storage_type()