[Refactor]: Change scheduler to param_scheduler (open-mmlab#121)

* [Refactor]: Change scheduler to param_scheduler

* [Fix]: Fix UT of param scheduler hook

Co-authored-by: Your <you@example.com>

mmengine/hooks/param_scheduler_hook.py

@@ -31,7 +31,7 @@ def after_train_iter(self,
                 In order to keep this interface consistent with other hooks, we
                 keep ``data_batch`` here. Defaults to None.
         """
-        for scheduler in runner.schedulers:
+        for scheduler in runner.param_schedulers:  # type: ignore
             if not scheduler.by_epoch:
                 scheduler.step()
 
@@ -41,6 +41,6 @@ def after_train_epoch(self, runner) -> None:
         Args:
             runner (Runner): The runner of the training process.
         """
-        for scheduler in runner.schedulers:
+        for scheduler in runner.param_schedulers:  # type: ignore
             if scheduler.by_epoch:
                 scheduler.step()

tests/test_hook/test_param_scheduler_hook.py

@@ -12,7 +12,7 @@ def test_after_iter(self):
         scheduler = Mock()
         scheduler.step = Mock()
         scheduler.by_epoch = False
-        Runner.schedulers = [scheduler]
+        Runner.param_schedulers = [scheduler]
         Hook.after_train_iter(Runner)
         scheduler.step.assert_called()
 
@@ -22,6 +22,6 @@ def test_after_epoch(self):
         scheduler = Mock()
         scheduler.step = Mock()
         scheduler.by_epoch = True
-        Runner.schedulers = [scheduler]
+        Runner.param_schedulers = [scheduler]
         Hook.after_train_epoch(Runner)
         scheduler.step.assert_called()