From 8f4247427c789c2bcdafcb5f5bedc01362998dbf Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@gmail.com>
Date: Sat, 12 Nov 2016 17:47:25 +1100
Subject: [PATCH] Rearranged WebPImagePlugin _accept for speed

---
 PIL/WebPImagePlugin.py | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/PIL/WebPImagePlugin.py b/PIL/WebPImagePlugin.py
index 6837b53be..eacc7c5a8 100644
--- a/PIL/WebPImagePlugin.py
+++ b/PIL/WebPImagePlugin.py
@@ -17,11 +17,9 @@ _VP8_MODES_BY_IDENTIFIER = {
 
 
 def _accept(prefix):
-    is_riff_file_format = prefix[:4] == b"RIFF"
-    is_webp_file = prefix[8:12] == b"WEBP"
-    is_valid_vp8_mode = prefix[12:16] in _VP8_MODES_BY_IDENTIFIER
-
-    return is_riff_file_format and is_webp_file and is_valid_vp8_mode
+    return (prefix[:4] == b"RIFF" # RIFF file format
+            and prefix[8:12] == b"WEBP" # WEBP file
+            and prefix[12:16] in _VP8_MODES_BY_IDENTIFIER) # Valid VP8 mode
 
 
 class WebPImageFile(ImageFile.ImageFile):