Fix few exp bugs

qlib/workflow/__init__.py

@@ -17,7 +17,7 @@ class QlibRecorder:
 
     @contextmanager
     def start(self, experiment_name):
-        run = self.start_exp(experiment_name, self.uri)
+        run = self.start_exp(experiment_name)
         try:
             yield run
         except:

qlib/workflow/exp.py

@@ -74,7 +74,7 @@ class MLflowExperiment(Experiment):
     def create_recorder(self):
         recorder = MLflowRecorder(self.id)
         self.recorders.append(recorder)
-        return recorders
+        return recorder
 
     def search_records(self, **kwargs):
         filter_string = "" if kwargs.get("filter_string") is None else kwargs.get("filter_string")

qlib/workflow/expm.py

@@ -9,7 +9,7 @@ from .exp import MLflowExperiment
 from .recorder import MLflowRecorder
 from ..log import get_module_logger
 
-logger = get_module_logger("workflow", "WARN")
+logger = get_module_logger("workflow", "WARNING")
 
 
 class ExpManager:
@@ -168,8 +168,9 @@ class MLflowExpManager(ExpManager):
         return self.active_recorder.start_run(experiment_id=experiment.id)
 
     def end_exp(self):
-        self.active_recorder.end_run()
-        self.active_recorder = None
+        if self.active_recorder is not None:
+            self.active_recorder.end_run()
+            self.active_recorder = None
 
     def __create_exp(self, experiment_name=None, uri=None):
         # init experiment