add tests and add to _isna_old

Author: joy-rosie

pandas/core/dtypes/missing.py

@@ -173,6 +173,8 @@ def _isna_old(obj):
     # hack (for now) because MI registers as ndarray
     elif isinstance(obj, ABCMultiIndex):
         raise NotImplementedError("isna is not defined for MultiIndex")
+    elif isinstance(obj, type):
+        return False
     elif isinstance(obj, (ABCSeries, np.ndarray, ABCIndexClass)):
         return _isna_ndarraylike_old(obj)
     elif isinstance(obj, ABCGeneric):

pandas/tests/dtypes/test_missing.py

@@ -86,6 +86,10 @@ def test_isna_isnull(self, isna_f):
         assert not isna_f(np.inf)
         assert not isna_f(-np.inf)
 
+        # type
+        assert not isna_f(type(pd.Series()))
+        assert not isna_f(type(pd.DataFrame()))
+
         # series
         for s in [
             tm.makeFloatSeries(),