timedelta fillna check

Author: jreback

pandas/core/internals.py

@@ -1886,7 +1886,7 @@ def fillna(self, value, **kwargs):
 
         # allow filling with integers to be
         # interpreted as seconds
-        if not isinstance(value, np.timedelta64):
+        if is_integer(value) and not isinstance(value, np.timedelta64):
             value = Timedelta(value, unit='s')
         return super(TimeDeltaBlock, self).fillna(value, **kwargs)
 
@@ -1917,11 +1917,11 @@ def _try_coerce_args(self, values, other):
         elif isinstance(other, Timedelta):
             other_mask = isnull(other)
             other = other.value
+        elif isinstance(other, timedelta):
+            other = Timedelta(other).value
         elif isinstance(other, np.timedelta64):
             other_mask = isnull(other)
             other = Timedelta(other).value
-        elif isinstance(other, timedelta):
-            other = Timedelta(other).value
         elif hasattr(other, 'dtype') and is_timedelta64_dtype(other):
             other_mask = isnull(other)
             other = other.astype('i8', copy=False).view('i8')