preprocess: Fix RemoveNaNClasses / Use existing HasClass

Author: lanzagar

Orange/preprocess/preprocess.py

@@ -9,6 +9,7 @@
 import bottleneck as bn
 
 import Orange.data
+from Orange.data.filter import HasClass
 from Orange.preprocess.util import _RefuseDataInConstructor
 from Orange.statistics import distribution
 from Orange.util import Reprable, Enum
@@ -216,11 +217,7 @@ def __call__(self, data):
         -------
         data : data set without rows with missing classes
         """
-        if len(data.Y.shape) > 1:
-            nan_cls = np.any(np.isnan(data.Y), axis=1)
-        else:
-            nan_cls = np.isnan(data.Y)
-        return data[~nan_cls]
+        return HasClass()(data)
 
 
 class Normalize(Preprocess):