Boiler Controller version of HotPi

#!/usr/tmp/env python
#This is based on Beta 0.8b of HotPi. Thank you to David for posting the code for HotPi and therefore to all the people who have contributed in the RPi forums

import os
import re
import RPi.GPIO as GPIO
import time
import math

def main():

    GPIO.setwarnings(False)
    GPIO.cleanup()
    GPIO.setmode(GPIO.BCM)

# set BCM pin number for the Boiler.
    BOILER = 18
    GPIO.setup(BOILER, GPIO.OUT)
    GPIO.output(BOILER, GPIO.HIGH)

# see if the one-wire "w1" interfaces are loaded
    modfile = open("/proc/modules")
    moduletext = modfile.read()
    modfile.close()
    if not (re.search("w1_gpio", moduletext) and re.search("w1_therm", moduletext)):

# if modules not found, install them
        os.system('sudo modprobe w1-gpio')
        os.system('sudo modprobe w1-therm')

# define serial number for the DS18B20 temperature sensor
    sensmaintemp = "/sys/bus/w1/devices/28-00000568ddcc/w1_slave" #inside sensor

# this reads the temperature and rounds the value to the nearest decimal and also does a crc check
    def currtemp():
        while(1):
            tfile = open(sensmaintemp)
            text = tfile.read()
            tfile.close()
            firstline  = text.split("\n")[0]
            crc_check = text.split("crc=")[1]
            crc_check = crc_check.split(" ")[1]
            if crc_check.find("YES")>=0:
                break
        secondline = text.split("\n")[1]
        temperaturedata = secondline.split(" ")[9]
        temperature = float(temperaturedata[2:])
        temperature = temperature / 1000.0
        temperature = round(temperature, 1)
        return temperature

# set desired temperature using value in "settemp = (XX)"
    def settemp():
        settemp = (67)
        return float(settemp)

# hold the temperature at the settemp. write status to file in /var/tmp
    def holdtemp():
        # the + or - of 0.5 is a heuristic value. modify to desired setting
        while currtemp() >= settemp() + 0.5:
           GPIO.output(BOILER, GPIO.HIGH)
           status = open("/var/tmp/temperaturedata.log", "w+")
           status.write(str(time.strftime("%H:%M:%S")) + " Current Temp is " + str(currtemp()) + " Boiler is off" + "\n")
           status.close()
           #print "Off loop", currtemp()
           time.sleep(1)
        else:
            while currtemp() <= settemp() - 0.5:
               GPIO.output(BOILER, GPIO.LOW)
               status = open("/var/tmp/temperaturedata.log", "w+")
               status.write(str(time.strftime("%H:%M:%S")) + " Current Temp is " + str(currtemp()) + " Boiler is on" + "\n")
               status.close()
               #print "On loop", currtemp()
               time.sleep(1)

# this constructs an infinite loop
    infloop = 1
    while infloop == 1 :
        holdtemp()

if __name__ == '__main__':
    main()