BUG: fill_value not being applied for mixed type frame #2191

Author: changhiskhan

pandas/core/frame.py

@@ -3320,7 +3320,7 @@ def _arith_op(left, right):
             # XXX no good for duplicate columns
             result = {}
             for col in this:
-                result[col] = func(this[col].values, other[col].values)
+                result[col] = _arith_op(this[col].values, other[col].values)
         else:
             result = _arith_op(this.values, other.values)
 

pandas/tests/test_frame.py

@@ -6086,6 +6086,13 @@ def test_combineAdd(self):
         comb = df1.combineAdd(df2)
         assert_frame_equal(comb, df3)
 
+        # mixed type GH2191
+        df1 = DataFrame({'A' : [1, 2], 'B' : [3, 4]})
+        df2 = DataFrame({'A' : [1, 2], 'C' : [5, 6]})
+        rs = df1.combineAdd(df2)
+        xp = DataFrame({'A' : [2, 4], 'B' : [3, 4.], 'C' : [5, 6.]})
+        assert_frame_equal(xp, rs)
+
         # TODO: test integer fill corner?
 
     def test_combineMult(self):