CPU usage with bottle.py and psutil

web_cpu.py

__author__ = 'muffo'

from bottle import route, response, run
from time import sleep
from psutil import cpu_percent
from json import dumps
import thread

cpu = None

def update_cpu(delay):
    global cpu
    while True:
        cpu = cpu_percent(interval=None, percpu=True)
        print "CPU Thread:", cpu
        sleep(delay)

@route('/cpu')
def hello():
    global cpu
    response.content_type = 'application/json'
    return dumps({"cpu": cpu})

thread.start_new_thread(update_cpu, (1, ))
run(host='localhost', port=8080, debug=True)