From 00d8ca9b6eee72b29198538dd24d4933c21d2fbb Mon Sep 17 00:00:00 2001
From: SergBobrovsky <SergBobrovsky@users.noreply.github.com>
Date: Fri, 29 May 2020 17:02:23 +0300
Subject: [PATCH] Update pyoo.py

---
 pyoo.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pyoo.py b/pyoo.py
index 37f0fc9..fd0012b 100644
--- a/pyoo.py
+++ b/pyoo.py
@@ -145,9 +145,9 @@ def _clean_slice(key, length):
     if not isinstance(stop, integer_types):
         raise TypeError('Cell indices must be integers, %s given.' % type(stop).__name__)
     if start < 0:
-        start = start + length
+        start += length
     if stop < 0:
-        stop = stop + length
+        stop += length
     start, stop = max(0, start), min(length, stop)
     if start == stop:
         raise ValueError('Cell slice can not be empty.')