Few minor fixes in Engine and Event

ignite/engine/deterministic.py

@@ -233,7 +233,7 @@ def _setup_engine(self) -> None:
         # Below we define initial counter value for _run_once_on_dataset to measure a single epoch
         if self.state.epoch_length is not None:
             iteration %= self.state.epoch_length
-        self._init_iter.append(iteration)
+        self._init_iter = iteration
 
         # restore rng state if in the middle
         in_the_middle = self.state.iteration % self._dataloader_len > 0 if self._dataloader_len is not None else False

ignite/engine/engine.py

@@ -132,7 +132,7 @@ def __init__(self, process_function: Callable[["Engine", Any], Any]):
         self._allowed_events = []  # type: List[EventEnum]
 
         self._dataloader_iter = None  # type: Optional[Iterator[Any]]
-        self._init_iter = []  # type: List[int]
+        self._init_iter = None  # type: Optional[int]
 
         self.register_events(*Events)
 
@@ -723,7 +723,7 @@ def switch_batch(engine):
             if self.should_terminate:
                 # If engine was terminated and now is resuming from terminated state
                 # we need to initialize iter_counter as 0
-                self._init_iter.append(0)
+                self._init_iter = 0
 
         self.state.dataloader = data
         return self._internal_run()
@@ -756,12 +756,12 @@ def _setup_dataloader_iter(self) -> None:
     def _setup_engine(self) -> None:
         self._setup_dataloader_iter()
 
-        if len(self._init_iter) == 0:
+        if self._init_iter is None:
             iteration = self.state.iteration
             # Below we define initial counter value for _run_once_on_dataset to measure a single epoch
             if self.state.epoch_length is not None:
                 iteration %= self.state.epoch_length
-            self._init_iter.append(iteration)
+            self._init_iter = iteration
 
     def _internal_run(self) -> State:
         self.should_terminate = self.should_terminate_single_epoch = False
@@ -832,12 +832,8 @@ def _run_once_on_dataset(self) -> float:
         start_time = time.time()
 
         # We need to setup iter_counter > 0 if we resume from an iteration
-        if len(self._init_iter) > 1:
-            raise RuntimeError(
-                "Internal error, len(self._init_iter) should 0 or 1, "
-                f"but got: {len(self._init_iter)}, {self._init_iter}"
-            )
-        iter_counter = self._init_iter.pop() if len(self._init_iter) > 0 else 0
+        iter_counter = 0 if self._init_iter is None else self._init_iter
+        self._init_iter = None
         should_exit = False
         try:
             if self._dataloader_iter is None:

ignite/engine/events.py

@@ -280,9 +280,9 @@ class CustomEvents(EventEnum):
     """Event attribute indicating epoch is ended."""
 
     STARTED = "started"
-    """triggered when engine’s run is started."""
+    """triggered when engine's run is started."""
     COMPLETED = "completed"
-    """"triggered when engine’s run is completed"""
+    """triggered when engine's run is completed"""
 
     ITERATION_STARTED = "iteration_started"
     """triggered when an iteration is started."""
@@ -297,7 +297,7 @@ class CustomEvents(EventEnum):
     """triggered after the batch is fetched."""
 
     DATALOADER_STOP_ITERATION = "dataloader_stop_iteration"
-    """"engine’s specific event triggered when dataloader has no more data to provide"""
+    """engine's specific event triggered when dataloader has no more data to provide"""
     TERMINATE = "terminate"
     """triggered when the run is about to end completely, after receiving terminate() call."""
     TERMINATE_SINGLE_EPOCH = "terminate_single_epoch"

tests/ignite/engine/test_engine.py

@@ -516,7 +516,7 @@ def test__setup_engine():
     data = list(range(100))
     engine.state.dataloader = data
     engine._setup_engine()
-    assert len(engine._init_iter) == 1 and engine._init_iter[0] == 10
+    assert engine._init_iter == 10
 
 
 def test_run_asserts():