From ecc8eaaf505f15a5a9840823e20c5cd3bd1914d0 Mon Sep 17 00:00:00 2001
From: MarcoGorelli <>
Date: Tue, 6 Dec 2022 18:35:11 +0000
Subject: [PATCH] perf

---
 pandas/_libs/tslib.pyx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/_libs/tslib.pyx b/pandas/_libs/tslib.pyx
index 418daafd30f55..6f58fecd1ac81 100644
--- a/pandas/_libs/tslib.pyx
+++ b/pandas/_libs/tslib.pyx
@@ -434,7 +434,7 @@ def first_non_null(values: ndarray) -> int:
         if (
             isinstance(val, str)
             and
-            (len(val) == 0 or val in ("now", "today", *nat_strings))
+            (len(val) == 0 or val in nat_strings or val in ("now", "today"))
         ):
             continue
         return i