Fixes for Python 3.9

Signed-off-by: Sreekanth <prsreekanth920@gmail.com>

Author: BulkBeing

pynumaflow/sourcer/_dtypes.py

@@ -169,7 +169,7 @@ def offsets(self) -> list[Offset]:
         return self._offsets
 
 
-@dataclass(slots=True)
+@dataclass
 class NackRequest:
     """
     Class for defining the request for negatively acknowledging an offset.
@@ -182,8 +182,17 @@ class NackRequest:
     >>> nack_request = NackRequest(offsets=[offset_val, offset_val])
     """
 
+    __slots__ = ("_offsets",)
     offsets: list[Offset]
 
+    def __init__(self, offsets: list[Offset]):
+        self._offsets = offsets
+
+    @property
+    def offsets(self) -> list[Offset]:
+        """Returns the offsets to be negatively acknowledged."""
+        return self._offsets
+
 
 @dataclass(init=False)
 class PendingResponse:

tests/source/test_async_source_err.py

@@ -92,13 +92,6 @@ def test_read_error(self) -> None:
                 )
                 for _ in generator_response:
                     pass
-            except BaseException as e:
-                self.assertTrue(
-                    f"{ERR_UDF_EXCEPTION_STRING}: TypeError("
-                    '"handle_async_error() missing 1 required positional argument: '
-                    "'exception_type'\")" in e.__str__()
-                )
-                return
             except grpc.RpcError as e:
                 grpc_exception = e
                 self.assertEqual(grpc.StatusCode.UNKNOWN, e.code())
@@ -138,12 +131,12 @@ def test_ack_error(self) -> None:
                 resp = stub.AckFn(request_iterator=request_generator(1, request, "ack"))
                 for _ in resp:
                     pass
-            except BaseException as e:
-                self.assertTrue("Got a runtime error from ack handler." in e.__str__())
-                return
             except grpc.RpcError as e:
                 self.assertEqual(grpc.StatusCode.UNKNOWN, e.code())
                 print(e.details())
+            except BaseException as e:
+                self.assertTrue("Got a runtime error from ack handler." in e.__str__())
+                return
         self.fail("Expected an exception.")
 
     def test_ack_no_handshake_error(self) -> None: