BUG: DataFrame.is_numeric needs to use inferred_type, closes #954

Author: lodagro

pandas/core/index.py

@@ -148,7 +148,7 @@ def is_monotonic(self):
             return False
 
     def is_numeric(self):
-        return issubclass(self.dtype.type, np.number)
+        return self.inferred_type in ['integer', 'floating']
 
     def is_datetype(self):
         for key in self.values:

pandas/tests/test_index.py

@@ -21,6 +21,7 @@ def setUp(self):
         self.strIndex = tm.makeStringIndex(100)
         self.dateIndex = tm.makeDateIndex(100)
         self.intIndex = tm.makeIntIndex(100)
+        self.floatIndex = tm.makeFloatIndex(100)
         self.empty = Index([])
         self.tuples = Index(zip(['foo', 'bar', 'baz'], [1, 2, 3]))
 
@@ -267,6 +268,12 @@ def testit(index):
     #     self.assert_(empty is NULL_INDEX)
     #     self.assert_(self.dateIndex[15:15] is NULL_INDEX)
 
+    def test_is_numeric(self):
+        self.assert_(not self.dateIndex.is_numeric())
+        self.assert_(not self.strIndex.is_numeric())
+        self.assert_(self.intIndex.is_numeric())
+        self.assert_(self.floatIndex.is_numeric())
+
     def test_is_all_dates(self):
         self.assert_(self.dateIndex.is_all_dates)
         self.assert_(not self.strIndex.is_all_dates)
@@ -829,6 +836,10 @@ def test_contains(self):
     def test_is_all_dates(self):
         self.assert_(not self.index.is_all_dates)
 
+    def test_is_numeric(self):
+        # MultiIndex is never numeric
+        self.assert_(not self.index.is_numeric())
+
     def test_getitem(self):
         # scalar
         self.assertEquals(self.index[2], ('bar', 'one'))

pandas/util/testing.py

@@ -159,6 +159,10 @@ def makeStringIndex(k):
 def makeIntIndex(k):
     return Index(range(k))
 
+def makeFloatIndex(k):
+    values = sorted(np.random.random_sample(k)) - np.random.random_sample(1)
+    return Index(values * (10 ** np.random.randint(0, 9)))
+
 def makeDateIndex(k):
     dates = list(DateRange(datetime(2000, 1, 1), periods=k))
     return Index(dates)