silence session close exception

pandas_ml_utils/__init__.py

@@ -1,5 +1,5 @@
 """Augment pandas DataFrame with methods for machine learning"""
-__version__ = '0.0.22'
+__version__ = '0.0.23'
 
 # imports to provide functionality via root import like import pandas_ml_utils as pmu; pmu.XY
 from pandas_ml_utils.pandas_utils_extension import *

pandas_ml_utils/model/models.py

@@ -353,7 +353,10 @@ def __setstate__(self, state):
 
     def __del__(self):
         if self.is_tensorflow:
-            self.session.close()
+            try:
+                self.session.close()
+            except AttributeError:
+                pass
 
     def __call__(self, *args, **kwargs):
         new_model = KerasModel(self.keras_model_provider,