From 819462a8ba19d6a320b182cfcd1119f280285de1 Mon Sep 17 00:00:00 2001
From: VanyaBelyaev <Ivan.Belyaev@cern.ch>
Date: Mon, 5 Aug 2024 17:03:47 +0200
Subject: [PATCH] Update histos.py

---
 ostap/histos/histos.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ostap/histos/histos.py b/ostap/histos/histos.py
index 5f408b1d..92c0e8ea 100755
--- a/ostap/histos/histos.py
+++ b/ostap/histos/histos.py
@@ -4337,7 +4337,7 @@ def _h1_effic4_ ( histo , cut_low  ) :
     """
 
     c1 = [ histo [ i ] for i in histo ]
-    c2 = c1.copy()
+    c2 = c1 [ : ]
     c2.reverse  ()
 
     ## for "natural" histograms make better treatment of first/last uncertainties