CLN: fix Exception type and tweak message GH5399

Author: y-p

pandas/stats/moments.py

@@ -196,7 +196,8 @@ def _get_corr(a, b):
 def _flex_binary_moment(arg1, arg2, f):
     if not (isinstance(arg1,(np.ndarray, Series, DataFrame)) and
             isinstance(arg2,(np.ndarray, Series, DataFrame))):
-        raise ValueError("arguments to moment function must be of type ndarray/DataFrame")
+        raise TypeError("arguments to moment function must be of type "
+                         "np.ndarray/Series/DataFrame")
 
     if isinstance(arg1, (np.ndarray,Series)) and isinstance(arg2, (np.ndarray,Series)):
         X, Y = _prep_binary(arg1, arg2)

pandas/stats/tests/test_moments.py

@@ -614,7 +614,7 @@ def test_rolling_corr_pairwise(self):
     def test_flex_binary_moment(self):
         # GH3155
         # don't blow the stack
-        self.assertRaises(ValueError, mom._flex_binary_moment,5,6,None)
+        self.assertRaises(TypeError, mom._flex_binary_moment,5,6,None)
 
     def test_corr_sanity(self):
         #GH 3155