Fix mypy error message in pandas/tests/indexes/test_numeric.py …

Use Optional to signal that the value may be either an `Index` or `None`.

Author: grigoriosgiann

pandas/tests/indexes/common.py

@@ -1,4 +1,5 @@
 import gc
+from typing import Optional, Type
 
 import numpy as np
 import pytest
@@ -30,7 +31,7 @@
 class Base:
     """ base class for index sub-class tests """
 
-    _holder = None
+    _holder: Optional[Type[Index]] = None
     _compat_props = ["shape", "ndim", "size", "nbytes"]
 
     def test_pickle_compat_construction(self):

setup.cfg

@@ -187,9 +187,6 @@ ignore_errors=True
 [mypy-pandas.tests.indexes.test_category]
 ignore_errors=True
 
-[mypy-pandas.tests.indexes.test_numeric]
-ignore_errors=True
-
 [mypy-pandas.tests.indexes.test_range]
 ignore_errors=True