From d0280a65387bbfbd70f28c24b6ae17f2d5c496d6 Mon Sep 17 00:00:00 2001
From: Giovanni Cavallin <37183651+mawanda-jun@users.noreply.github.com>
Date: Tue, 11 Sep 2018 10:30:42 +0200
Subject: [PATCH] From KeyError to ValueError when saving image

When saving an image, if the extension is not determined it raises a ValueError (while internally it manages a KeyError) so I propose this change
---
 src/PIL/Image.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/PIL/Image.py b/src/PIL/Image.py
index c58952657..2b248ab3e 100644
--- a/src/PIL/Image.py
+++ b/src/PIL/Image.py
@@ -1894,7 +1894,7 @@ class Image(object):
            parameter should always be used.
         :param params: Extra parameters to the image writer.
         :returns: None
-        :exception KeyError: If the output format could not be determined
+        :exception ValueError: If the output format could not be determined
            from the file name.  Use the format option to solve this.
         :exception IOError: If the file could not be written.  The file
            may have been created, and may contain partial data.