how to capture wireless data frame using scapy in python

Question

I am using the following code to capture only data packets from a wireless network but following code is not working for the data packets it worked only for management frame. So what changes should be made to capture the data frames?

def PacketHandler(pkt) :                                          
   if pkt.haslayer(Dot11) :                      
           if pkt.type == 2 and pkt.subtype == 0 :                
                TCP IP data



sniff(iface="mon0", prn = PacketHandler)

code taken from: http://hackoftheday.securitytube.net/2013/03/wi-fi-sniffer-in-10-lines-of-python.html