From aa31e889a05cfb7a9e30cc691363f18c2d902ab0 Mon Sep 17 00:00:00 2001
From: Sam Gross <sgross@fb.com>
Date: Fri, 26 May 2017 13:17:25 -0700
Subject: [PATCH] Fix ResourceWarning due to Image.open(path)

See https://github.com/python-pillow/Pillow/issues/835
---
 torchvision/datasets/folder.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/torchvision/datasets/folder.py b/torchvision/datasets/folder.py
index 3f15c647103..a0f3dc595eb 100644
--- a/torchvision/datasets/folder.py
+++ b/torchvision/datasets/folder.py
@@ -39,7 +39,10 @@ def make_dataset(dir, class_to_idx):
 
 
 def pil_loader(path):
-    return Image.open(path).convert('RGB')
+    # open path as file to avoid ResourceWarning (https://github.com/python-pillow/Pillow/issues/835)
+    with open(path, 'rb') as f:
+        with Image.open(f) as img:
+            return img.convert('RGB')
 
 
 def accimage_loader(path):