ADD raise exception when failing to create sklearn flow (#479)

mfeurer · web-flow · commit a954ce276287 · 2018-06-19T09:52:46.000+02:00
* ADD raise exception when failing to create sklearn flow

* Update changelog
diff --git a/doc/progress.rst b/doc/progress.rst
@@ -14,6 +14,9 @@ Changelog
 * Added serialize run / deserialize run function (for saving runs on disk before uploading)
 * FIX: fixed bug related to listing functions (returns correct listing size)
 * made openml.utils.list_all a hidden function (should be accessed only by the respective listing functions)
+* Improve error handling for issue `#479 <https://github.com/openml/openml-python/pull/479>`_:
+  the OpenML connector fails earlier and with a better error message when
+  failing to create a flow from the OpenML description.
 
 0.3.0
 ~~~~~
diff --git a/openml/flows/flow.py b/openml/flows/flow.py
@@ -313,12 +313,13 @@ def _from_dict(cls, xml_dict):
         # try to parse to a model because not everything that can be
         # deserialized has to come from scikit-learn. If it can't be
         # serialized, but comes from scikit-learn this is worth an exception
-        try:
+        if (
+            arguments['external_version'].startswith('sklearn==')
+            or ',sklearn==' in arguments['external_version']
+        ):
             from .sklearn_converter import flow_to_sklearn
             model = flow_to_sklearn(flow)
-        except Exception as e:
-            if arguments['external_version'].startswith('sklearn'):
-                raise e
+        else:
             model = None
         flow.model = model
 
diff --git a/openml/flows/sklearn_converter.py b/openml/flows/sklearn_converter.py
@@ -394,12 +394,8 @@ def _deserialize_model(flow, **kwargs):
         parameter_dict[name] = rval
 
     module_name = model_name.rsplit('.', 1)
-    try:
-        model_class = getattr(importlib.import_module(module_name[0]),
-                              module_name[1])
-    except:
-        warnings.warn('Cannot create model %s for flow.' % model_name)
-        return None
+    model_class = getattr(importlib.import_module(module_name[0]),
+                          module_name[1])
 
     return model_class(**parameter_dict)
 
