From a36ca29ea0d0e5694638eaba40bf19cf9c1238be Mon Sep 17 00:00:00 2001
From: Samuel GIFFARD <samuel@giffard.co>
Date: Mon, 1 Mar 2021 18:09:34 +0900
Subject: [PATCH] to_offset was not using the compiled regex

Resolves #39988.
---
 pandas/_libs/tslibs/offsets.pyx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/_libs/tslibs/offsets.pyx b/pandas/_libs/tslibs/offsets.pyx
index 2d4704ad3bda6..4e6e5485b2ade 100644
--- a/pandas/_libs/tslibs/offsets.pyx
+++ b/pandas/_libs/tslibs/offsets.pyx
@@ -3579,7 +3579,7 @@ cpdef to_offset(freq):
         stride_sign = None
 
         try:
-            split = re.split(opattern, freq)
+            split = opattern.split(freq)
             if split[-1] != "" and not split[-1].isspace():
                 # the last element must be blank
                 raise ValueError("last element must be blank")