Merge pull request #6681 from markotoplak/display-nans

Display NaNs in StringVariable as "?"

Author: janezd

Orange/data/tests/test_variable.py

@@ -634,6 +634,8 @@ def test_val(self):
         self.assertEqual(a.str_val(""), "?")
         self.assertEqual(a.str_val(Value(a, "")), "?")
         self.assertEqual(a.repr_val(Value(a, "foo")), '"foo"')
+        self.assertEqual(a.str_val(np.nan), "?")
+        self.assertEqual(a.str_val(None), "?")
 
 
 @variabletest(TimeVariable)

Orange/data/variable.py

@@ -10,6 +10,7 @@
 from pickle import PickleError
 
 import numpy as np
+import pandas
 import scipy.sparse as sp
 
 from Orange.data import _variable
@@ -905,6 +906,8 @@ def str_val(val):
             if not val.value:
                 return "?"
             val = val.value
+        if pandas.isnull(val):
+            return "?"
         return str(val)
 
     def repr_val(self, val):