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

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

tools/editconf.py

@@ -76,7 +76,8 @@ for setting in settings:
 
 found = set()
 buf = ""
-input_lines = list(open(filename))
+with open(filename, "r") as f:
+        input_lines = list(f)
 
 while len(input_lines) > 0:
 	line = input_lines.pop(0)

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

tools/readable_bash.py

@@ -124,13 +124,14 @@ def generate_documentation():
  """)
 
 	parser = Source.parser()
-	for line in open("setup/start.sh"):
-		try:
-			fn = parser.parse_string(line).filename()
-		except:
-			continue
-		if fn in ("setup/start.sh", "setup/preflight.sh", "setup/questions.sh", "setup/firstuser.sh", "setup/management.sh"):
-			continue
+	with open("setup/start.sh", "r") as start_file: 
+                for line in start_file:
+                        try:
+                                fn = parser.parse_string(line).filename()
+                        except:
+                                continue
+                        if fn in ("setup/start.sh", "setup/preflight.sh", "setup/questions.sh", "setup/firstuser.sh", "setup/management.sh"):
+                                continue
 
 		import sys
 		print(fn, file=sys.stderr)
@@ -401,7 +402,8 @@ class BashScript(Grammar):
 	@staticmethod
 	def parse(fn):
 		if fn in ("setup/functions.sh", "/etc/mailinabox.conf"): return ""
-		string = open(fn).read()
+		with open(fn, "r") as f:
+			string = f.read()
 
 		# tokenize
 		string = re.sub(".* #NODOC\n", "", string)