bpo-34500: Fix ResourceWarning in difflib.py (GH-8926)
The change to Tools/scripts/diff.py effectively backports part of
a2637729f23dc993e820fd92f0d1759ad714c9b2.
The test code changed in Doc/library/difflib.rst is not present in current 3.x.
diff --git a/Doc/library/difflib.rst b/Doc/library/difflib.rst
index c6bf3ef..01a3bfc 100644
--- a/Doc/library/difflib.rst
+++ b/Doc/library/difflib.rst
@@ -757,8 +757,10 @@
# we're passing these as arguments to the diff function
fromdate = time.ctime(os.stat(fromfile).st_mtime)
todate = time.ctime(os.stat(tofile).st_mtime)
- fromlines = open(fromfile, 'U').readlines()
- tolines = open(tofile, 'U').readlines()
+ with open(fromfile, 'U') as f:
+ fromlines = f.readlines()
+ with open(tofile, 'U') as f:
+ tolines = f.readlines()
if options.u:
diff = difflib.unified_diff(fromlines, tolines, fromfile, tofile,