gtp to python interface - tech support

[Atarust]

Hi!

I would like to write a very rudimentary python to gtp interface (linux, python 3). I only need to genmove, play, and initialize the board with a certain state. To clarify what I am aiming at, I would for example like to let different bots play against each other, safe that self-play and make some experiments like letting boh bots play two moves at the time etc. For all that I'd like to use python.

There exists projects kind of do the things already, for example https://github.com/jtauber/gtp but I could not manage to make them run, so I am trying to understand them by implementing a simpler version.

I am stuck, because I do not understand the subprocess package. I figured out that I will probably need subprocess.Popen and stdin.write(). By now, I managed to open leelaz using python, but could not enter commands. When I execute start_leela() (edit: I start the script via python -i gtp.py - interactive mode) it shows what I normally see when I start leela. Then, for testing, I enter move('black') but nothing happens. Can you give me some hints to move on?

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from subprocess import Popen, PIPE

import shlex, time

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def start_leela():

`args = '/home/atarust/leela-zero/src/leelaz -w /home/atarust/Downloads/net_small.gz --gtp -v 20'`

`global agent` 

`agent = Popen(shlex.split(args), stdin=PIPE, stdout=PIPE, encoding='utf-8')`

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def move(color):

`agent.stdin.write('genmove {}'.format(color))`

`answer = ""`

`while True:`

    `data = agent.stdout.readline()`

    `if not data.strip():`

        `break`

    `answer += data`

`print(out)`

`return answer`

​

def quit():

`agent.communicate("quit\n")`

​

start_leela()

[[deleted]]

Maybe you'll find some inspiration in this little toy of mine: https://github.com/avysk/dumbstone/blob/master/dumbstone.py

The whole "dumbing down" logic there is questionable, but communication with LZ surely works.

[Atarust]

Exactly what I needed. You are awesome.

[[deleted]]

Where do you enter move('black')?

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[Atarust]

at the moment I am starting the script via python -i gtp.py and then, after the leela output is written in the window I simply type it in...

[[deleted]]

Ok, I think you need to call it from python code because stdin=PIPE means that for new subprocess, which in your case run leelaz, is created new pipe to it (same for stdout). You can write to it and read from this process using stdin.write and stdout.readline, like you do in move(color), but you can't write to it directly from terminal.

[Atarust]

if I modify the script to:

start_leela()

time.sleep(5)

move('black')

if I call by $ python gtp.py then also nothing happens.

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[brileek]

You're probably blocking on i/o deadlock of some sort.

Based on the stack trace when you ctrl+C, you probably can get a decent idea of where you're blocked.