Vanilla Minecraft runner

run.py

#!/usr/bin/python3

from subprocess import Popen
from os import path
from platform import system
from uuid import uuid4


def run_game(game_path, game_data, main_class, version, uuid=str(uuid4()), xmx=1024, max_perm_size=128, more=list()):
    """
    :type game_path: str
    :type game_data: str
    :type main_class: str
    :type version: str
    :type uuid: str
    :type xmx: int
    :type max_perm_size: int
    :type more: list
    """
    path_delimiter = ";" if system() == "Windows" else ":"

    args = [
        "java",
        "-XX:+UseConcMarkSweepGC",
        "-XX:+CMSIncrementalMode",
        "-XX:-UseAdaptiveSizePolicy",
        "-Xmn128M",
        "-Djava.library.path=" + path.join(game_path, "natives"),
        "-cp",
        path.join(game_path, "libs", "*") + path_delimiter + path.join(game_path, "minecraft.jar"),
        main_class,
        "--version", version,
        "--gameDir", game_data,
        "--assetsDir", path.join(game_path, "assets"),
        "--assetIndex", version,
        "--userProperties", "{}",
        "--accessToken", "123456",
        "--uuid", uuid,
        "-Xms" + str(xmx) + "M",
        "-Xmx" + str(xmx) + "M",
        "-XX:MaxPermSize=" + str(max_perm_size) + "M",
        "-Dfml.ignorePatchDiscrepancies=true"
    ] + more

    pid = Popen(args).pid
    return pid

if __name__ == '__main__':
    run_game(game_path="game", game_data="gamedata", main_class="net.minecraft.client.main.Main", 
             version="1.7.10", xmx=1024)