[bessctl]: show pipeline fails with python 3.7

[krsna1729]

Traceback (most recent call last):
  File "/bin/bessctl", line 186, in <module>
    main()
  File "/bin/bessctl", line 183, in main
    run_cli(io.StringIO('\n'.join(cmds)))
  File "/bin/bessctl", line 159, in run_cli
    cli.loop()
  File "/bin/bessctl", line 134, in loop
    super(BESSCLI, self).loop()
  File "/opt/bess/bessctl/cli.py", line 528, in loop
    self.process_one_line()
  File "/opt/bess/bessctl/cli.py", line 440, in process_one_line
    self.call_func(func, args)
  File "/bin/bessctl", line 95, in call_func
    super(BESSCLI, self).call_func(func, args)
  File "/opt/bess/bessctl/cli.py", line 411, in call_func
    func(*args)
  File "/opt/bess/bessctl/commands.py", line 1405, in show_pipeline
    cli.fout.write(_draw_pipeline(cli, 'pkts', '', graph_args=opts))
  File "/opt/bess/bessctl/commands.py", line 1359, in _draw_pipeline
    print('[%s]' % node_labels[m.name], file=f.stdin)
TypeError: a bytes-like object is required, not 'str'

[JanonWang]

I met the same problem and solved it by shifting to python2.7

[krsna1729]

Context - I was using 2.7 and wanted to move to 3.7

[fshahinfar1]

I think it is good to be mentioned that BESS needs python2.7 some where in installation guide.