try:
for i in range(0, args.instances):
cmd = u"exec sudo "
- cmd += f"ip netns exec {args.namespace} " if args.namespace else u""
+ cmd += (
+ f"ip netns exec {args.namespace} "
+ if args.namespace else u""
+ )
cmd += f"iperf3 "
cmd += f"--client {args.host} "
cmd += f"--bind {args.bind} "