Catch either OutOfBoundsTimedelta or OverflowError in CFTimeIndex.__s…

…ub__ and CFTimeIndex.__rsub__ (#5154)

xarray/coding/cftimeindex.py

@@ -43,6 +43,7 @@
 import warnings
 from datetime import timedelta
 from distutils.version import LooseVersion
+from typing import Tuple, Type
 
 import numpy as np
 import pandas as pd
@@ -59,10 +60,11 @@
 REPR_ELLIPSIS_SHOW_ITEMS_FRONT_END = 10
 
 
-if LooseVersion(pd.__version__) > LooseVersion("1.2.3"):
-    OUT_OF_BOUNDS_TIMEDELTA_ERROR = pd.errors.OutOfBoundsTimedelta
-else:
-    OUT_OF_BOUNDS_TIMEDELTA_ERROR = OverflowError
+OUT_OF_BOUNDS_TIMEDELTA_ERRORS: Tuple[Type[Exception], ...]
+try:
+    OUT_OF_BOUNDS_TIMEDELTA_ERRORS = (pd.errors.OutOfBoundsTimedelta, OverflowError)
+except AttributeError:
+    OUT_OF_BOUNDS_TIMEDELTA_ERRORS = (OverflowError,)
 
 
 def named(name, pattern):
@@ -568,7 +570,7 @@ def __sub__(self, other):
         elif _contains_cftime_datetimes(np.array(other)):
             try:
                 return pd.TimedeltaIndex(np.array(self) - np.array(other))
-            except OUT_OF_BOUNDS_TIMEDELTA_ERROR:
+            except OUT_OF_BOUNDS_TIMEDELTA_ERRORS:
                 raise ValueError(
                     "The time difference exceeds the range of values "
                     "that can be expressed at the nanosecond resolution."
@@ -579,7 +581,7 @@ def __sub__(self, other):
     def __rsub__(self, other):
         try:
             return pd.TimedeltaIndex(other - np.array(self))
-        except OUT_OF_BOUNDS_TIMEDELTA_ERROR:
+        except OUT_OF_BOUNDS_TIMEDELTA_ERRORS:
             raise ValueError(
                 "The time difference exceeds the range of values "
                 "that can be expressed at the nanosecond resolution."