From 8875df9ad9f5fc8b314e2c1bf4be2d807843442b Mon Sep 17 00:00:00 2001
From: Richard Shadrach <rhshadrach@gmail.com>
Date: Sat, 2 Aug 2025 13:43:10 -0400
Subject: [PATCH] BUG: Change default of observed in SeriesGroupBy

---
 pandas/core/series.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/core/series.py b/pandas/core/series.py
index 63ef68f202a6e..6ae03f2464f76 100644
--- a/pandas/core/series.py
+++ b/pandas/core/series.py
@@ -1972,7 +1972,7 @@ def groupby(
         as_index: bool = True,
         sort: bool = True,
         group_keys: bool = True,
-        observed: bool = False,
+        observed: bool = True,
         dropna: bool = True,
     ) -> SeriesGroupBy:
         from pandas.core.groupby.generic import SeriesGroupBy