class Agent(Thread):
    def __init__(self, url):
        Thread.__init__(self)
        self.url = url

    def run(self):
	response = urllib2.urlopen(url)
	print float(response.read())/0.00062137

class MetarReader:

	def __init__(self, Config):
		self.myConfig = Config
		self.visibility_m = self.myConfig.visMaxHighLevel

	def getVisibility(self):
	        t = Agent(url)
	        t.start()