Online fix

- Skip duplicated qlib.auto_init()
- Fix TSDatasetH flt_col bug!
- Resolve qlib log attribute confliction
- Trainer API enhancement
- More docs and user-friendly warning

qlib/workflow/expm.py

@@ -351,6 +351,15 @@ class MLflowExpManager(ExpManager):
             experiment_id is not None or experiment_name is not None
         ), "Please input at least one of experiment/recorder id or name before retrieving experiment/recorder."
         if experiment_id is not None:
+            try:
+                experiment_id = int(experiment_id)
+            except ValueError as e:
+                msg = "The `experiment_id` for mlflow backend must be `int`"
+                logger.error(msg)
+                # We have to raise type error here
+                # - The error looks like type error
+                # - Value Error will be catched
+                raise TypeError(msg)
             try:
                 exp = self.client.get_experiment(experiment_id)
                 if exp.lifecycle_stage.upper() == "DELETED":