diff --git a/src/morevna.py b/src/morevna.py
--- a/src/morevna.py
+++ b/src/morevna.py
@@ -13,38 +13,39 @@ from server import Miniserver
 
 def _checkFile(f):
 	if not os.path.isfile(f):
-		print("invalid file specified:",f,file=sys.stderr)
+		print("invalid file specified:", f, file=sys.stderr)
 		sys.exit(1)
 
 
 def buildTree(args):
 	_checkFile(args.datafile)
 	if os.path.isfile(args.treefile):
-		treeMod=os.stat(args.treefile).st_mtime
-		dataMod=os.stat(args.datafile).st_mtime
+		treeMod = os.stat(args.treefile).st_mtime
+		dataMod = os.stat(args.datafile).st_mtime
 		if dataMod<treeMod and not args.force:
 			print("tree file is up to date")
 			return
 
-	tree=HashTree.fromFile(args.datafile)
+	tree = HashTree.fromFile(args.datafile)
 	tree.save(args.treefile)
 
+
 def push(args):
 	_checkFile(args.datafile)
 	if args.tree:
 		_checkFile(args.tree)
-	if args.host: conf.hosts=[args.host]
-	if args.port: conf.port=args.port
+	if args.host: conf.hosts = [args.host]
+	if args.port: conf.port = args.port
 
-	c=Client(args.datafile,args.tree)
+	c = Client(args.datafile,args.tree)
 	for h in conf.hosts:
-		host=splitHost(h,conf.port)
+		host = splitHost(h,conf.port)
 		stats.reset()
 		try:
 			with ClientConnection(*host) as con:
 				c.setConnection(con)
 				c.init("push")
-				blocksToTransfer=c.negotiate()
+				blocksToTransfer = c.negotiate()
 				c.sendData(blocksToTransfer)
 			print()
 			print(stats.report())
@@ -59,17 +60,17 @@ def pull(args):
 	_checkFile(args.datafile)
 	if args.tree:
 		_checkFile(args.tree)
-	if args.host: conf.hosts=[args.host]
-	if args.port: conf.port=args.port
+	if args.host: conf.hosts = [args.host]
+	if args.port: conf.port = args.port
 
-	c=Client(args.datafile,args.tree)
-	host=splitHost(conf.hosts[0],conf.port)
+	c = Client(args.datafile, args.tree)
+	host = splitHost(conf.hosts[0], conf.port)
 	try:
 		with ClientConnection(*host) as con:
 			c.setConnection(con)
 			c.init("pull")
-			blocksToTransfer=c.negotiate()
-			c.pullData(blocksToTransfer,args.force)
+			blocksToTransfer = c.negotiate()
+			c.pullData(blocksToTransfer, args.force)
 		print()
 		print(stats.report())
 	except FailedConnection: pass
@@ -77,53 +78,54 @@ def pull(args):
 		print("Server {0}:{1} denied connection.".format(*host))
 		print(e)
 
+
 def serve(args):
 	_checkFile(args.datafile)
 	if args.tree:
 		_checkFile(args.tree)
-	if args.host: conf.hosts.insert(0,args.host)
-	if args.port: conf.port=args.port
+	if args.host: conf.hosts.insert(0, args.host)
+	if args.port: conf.port = args.port
 
 	try:
-		s=Miniserver(args.datafile,args.tree)
+		s = Miniserver(args.datafile,args.tree)
 		spawnDaemon(s.serve)
 	except Exception as e:
-		log.exception("exception: %s",e)
-		print("Failed to start:\n  ",e)
+		log.exception("exception: %s", e)
+		print("Failed to start:\n  ", e)
 
 
-parser=ArgumentParser()
-subparsers=parser.add_subparsers()
+parser = ArgumentParser()
+subparsers = parser.add_subparsers()
 
-pBuild=subparsers.add_parser("build")
-pBuild.add_argument("-f","--force",action="store_true",help="force tree rebuild")
+pBuild = subparsers.add_parser("build")
+pBuild.add_argument("-f", "--force", action="store_true", help="force tree rebuild")
 pBuild.add_argument("treefile", help="stored hash tree location")
 pBuild.add_argument("datafile")
 pBuild.set_defaults(func=buildTree)
 
-pUpdate=subparsers.add_parser("push")
-pUpdate.add_argument("-p","--port",type=int)
+pUpdate = subparsers.add_parser("push")
+pUpdate.add_argument("-p", "--port", type=int)
 pUpdate.add_argument("--host")
-pUpdate.add_argument("-t","--tree",help="stored hash tree location")
+pUpdate.add_argument("-t", "--tree", help="stored hash tree location")
 pUpdate.add_argument("datafile")
 pUpdate.set_defaults(func=push)
 
-pUpdate=subparsers.add_parser("pull")
-pUpdate.add_argument("-p","--port",type=int)
+pUpdate = subparsers.add_parser("pull")
+pUpdate.add_argument("-p", "--port", type=int)
 pUpdate.add_argument("--host")
-pUpdate.add_argument("-t","--tree",help="stored hash tree location")
-pUpdate.add_argument("-f","--force",action="store_true",help="ignore lock file")
+pUpdate.add_argument("-t", "--tree", help="stored hash tree location")
+pUpdate.add_argument("-f", "--force", action="store_true", help="ignore lock file")
 pUpdate.add_argument("datafile")
 pUpdate.set_defaults(func=pull)
 
-pServe=subparsers.add_parser("serve")
-pServe.add_argument("-p","--port",type=int)
+pServe = subparsers.add_parser("serve")
+pServe.add_argument("-p", "--port", type=int)
 pServe.add_argument("--host")
-pServe.add_argument("-t","--tree",help="stored hash tree location")
+pServe.add_argument("-t", "--tree", help="stored hash tree location")
 pServe.add_argument("datafile")
 pServe.set_defaults(func=serve)
 
-args=parser.parse_args()
+args = parser.parse_args()
 try: args.func(args)
 except AttributeError:
 	parser.print_help()