mod

pandas/core/internals.py

@@ -1669,7 +1669,7 @@ def fillna(self, value, **kwargs):
 
         # allow filling with integers to be
         # interpreted as seconds
-        if not isinstance(value, np.timedelta64):
+        if not isinstance(value, np.timedelta64) and is_integer(value):
             value = Timedelta(value, unit='s')
         return super(TimeDeltaBlock, self).fillna(value, **kwargs)
 
@@ -1710,9 +1710,7 @@ def _try_coerce_args(self, values, other):
             other = other.astype('i8', copy=False).view('i8')
         else:
             # scalar
-            other = Timedelta(other)
-            other_mask = isnull(other)
-            other = other.value
+            raise TypeError
 
         return values, values_mask, other, other_mask