chore(python open): Refactor open and gzip.open to use context manager (#2203)

Co-authored-by: Hugh Secker-Walker <hsw+miac@hodain.net>

tools/parse-nginx-log-bootstrap-accesses.py

@@ -17,13 +17,8 @@ accesses = set()
 # Scan the current and rotated access logs.
 for fn in glob.glob("/var/log/nginx/access.log*"):
 	# Gunzip if necessary.
-	if fn.endswith(".gz"):
-		f = gzip.open(fn)
-	else:
-		f = open(fn, "rb")
-
 	# Loop through the lines in the access log.
-	with f:
+	with (gzip.open if fn.endswith(".gz") else open)(fn, "rb") as f:
 		for line in f:
 			# Find lines that are GETs on the bootstrap script by either curl or wget.
 			# (Note that we purposely skip ...?ping=1 requests which is the admin panel querying us for updates.)
@@ -43,7 +38,8 @@ for date, ip in accesses:
 # Since logs are rotated, store the statistics permanently in a JSON file.
 # Load in the stats from an existing file.
 if os.path.exists(outfn):
-	existing_data = json.load(open(outfn))
+	with open(outfn, "r") as f:
+		existing_data = json.load(f)
 	for date, count in existing_data:
 		if date not in by_date:
 			by_date[date] = count