LifePreserver - Script to limit players' time on a minecraft server

preserver

#! /usr/bin/env python
# LifePreserver - Time limiting script for Minecraft servers
import sys
from subprocess import Popen, PIPE
from collections import Counter
from datetime import datetime
from pytz import timezone
from time import sleep

START_HOUR = 9
DAILY_CAP = 240
TIMEZONE = timezone('US/Central')
accounted_day = None
minutes_used = Counter()

proc = Popen(sys.argv[1:], stdin=PIPE, stdout=PIPE)

def readline():
    rv = proc.stdout.readline().strip()
    print rv
    return rv

def writeline(val):
    print ">", val
    proc.stdin.write(val + "\n")

def list_players():
    writeline('/list')

    while 'There are' not in readline():
        pass

    names = readline().partition(': ')[2]
    if not names: return []
    return names.split(', ')

def tell(player, message):
    writeline('/tell ' + player + ' ' + message)

def kick(player, message):
    writeline('/kick ' + player + ' ' + message)

def check_and_kick():
    global accounted_day
    global minutes_used
    
    # Check that the accounting is for today, else reset the count
    today = datetime.now(TIMEZONE).toordinal()
    if today != accounted_day:
        accounted_day = today
        minutes_used = Counter()

    players = list_players()
    for player in players:
        minutes_used[player] += 1
        mins = minutes_used[player]

        if datetime.now(TIMEZONE).hour < START_HOUR:
            kick(player, "It's too early to play Minecraft. The server opens again at {}:00".format(START_HOUR))
        if mins >= DAILY_CAP:
            kick(player, "Time's up for today")
        elif (mins % 30 == 0) or (mins >= DAILY_CAP - 5): # Will be kicked soon
            tell(player, 'You have {} minutes of play time left.'.format(DAILY_CAP - mins))
        elif mins == 1: # First login of the day
            tell(player, 'You will be able to play on this server for {} minutes today'.format(DAILY_CAP))
            tell(player, 'After your time runs out, you will be kicked automatically.')

try:
    while True:
        sleep(60)
        check_and_kick()
except:
    proc.terminate()