Python Event Handler

I am trying to implement an event handler of sort. I am try to collect sample network captures using a external process using Popen and it writes an XML file. I parse the xml file to collect what ever information I require. But I do开发者_JAVA技巧 not want to terminate the process until the number of packets has reached a certain limit.

def getPacketCount(xmlfile, count, pid):
    while 1:
        try:
            parser = minidom.parse(xmlfile)
            wlan = parser.getElementsByTagName('wireless-network')[0]
            pkt = wlan.getElementsByTagName('packets')[1]
            packetCount = pkt.getElementsByTagName('total').childNodes[0].data
            if packetCount>count:
                #Call event handler to kill process with given pid.
        except AttributeError, TypeError:
            print "AttributeError: Accessing file again"`

Note: I am implementing this with Django to handle database operations.