Python 2 mqtt cpu tem, cpu load and disk usage monitor

# Python 2 script to monitor cpu load, cpu temperature and free space,
# on a Raspberry Pi computer and publish the data to a MQTT server.

from __future__ import division
import subprocess, time, socket, os
import paho.mqtt.client as paho

#get device host name - used in mqtt topic
hostname = socket.gethostname()

#mqtt server configuration
mqtt_host = "mqtt_host"
mqtt_user = "mqtt_user"
mqtt_password = "mqtt_password"
mqtt_port = "1883"

def check_used_space(path):
    st = os.statvfs(path)
    free_space = st.f_bavail * st.f_frsize
    total_space = st.f_blocks * st.f_frsize
    used_space = int(100 - ((free_space / total_space) * 100))
    return used_space

def check_cpu_load():
    #bash command to get cpu load from uptime command
    p = subprocess.Popen("uptime", shell=True, stdout=subprocess.PIPE).communicate()[0]
    cpu_load = p.split("average:")[1].split(",")[0].replace(' ', '')
    return cpu_load

def check_cpu_temp():
    #bash command to get rpi cpu temp
    full_cmd = "/opt/vc/bin/vcgencmd measure_temp"
    p = subprocess.Popen(full_cmd, shell=True, stdout=subprocess.PIPE).communicate()[0]
    cpu_temp = p.replace('\n', ' ').replace('\r', '').split("=")[1].split("'")[0]
    return cpu_temp

if __name__ == '__main__':
    #check cpu load
    cpu_load = check_cpu_load()
    #check cpu temp
    cpu_temp = check_cpu_temp()
    #check used space
    used_space = check_used_space('/')

    #connect to mqtt server
    client = paho.Client()
    client.username_pw_set(mqtt_user, mqtt_password)
    client.connect(mqtt_host, mqtt_port)

    #publish cpu load mqtt message
    client.publish(hostname+"/cpuload", cpu_load, qos=1)
    time.sleep(1)

    #publish cpu temperature mqtt message
    client.publish(hostname+"/cputemp", cpu_temp, qos=1)
    time.sleep(1)

    #publish used space mqtt message
    client.publish(hostname+"/diskusage", used_space, qos=1)

    #disconect from mqtt server
    client.disconnect()