Applied requested changes

Author: gkonefal-reef

doc/source/whatsnew/v0.21.1.txt

@@ -56,7 +56,7 @@ Documentation Changes
 
 Bug Fixes
 ~~~~~~~~~
-- Bug in :meth:`fillna` where maximum recursion depth gets exceeded in comparison (:issue:`18159`).
+- Bug in :meth:`Series.fillna` which was raising RuntimeError when got large integer (:issue:`18159`).
 
 
 Conversion

pandas/core/internals.py

@@ -1898,7 +1898,7 @@ def _can_hold_element(self, element):
             return issubclass(tipo.type,
                               (np.floating, np.integer, np.complexfloating))
         return (isinstance(element,
-                           (float, int, complex, np.float_, np.int_)) and
+                           (float, int, complex, np.float_, np.int_, compat.long)) and
                 not isinstance(element, (bool, np.bool_)))
 
     def should_store(self, value):

pandas/tests/internals/test_internals.py

@@ -1224,6 +1224,7 @@ class TestCanHoldElement(object):
         (1.0, 'f8'),
         (2**63, 'f8'),
         (1j, 'complex128'),
+        (2**63, 'complex128'),
         (True, 'bool'),
         (np.timedelta64(20, 'ns'), '<m8[ns]'),
         (np.datetime64(20, 'ns'), '<M8[ns]'),