How can I filter a pcap file by specific protocol using python?

Question

I have some pcap files and I want to filter by protocol, i.e., if I want to filter by HTTP protocol, anything but HTTP packets will remain in the pcap file.

There is a tool called openDPI, and it's perfect for what I need, but there is no wrapper for python language.

Does anyone knows any python modules that can do what I need?

Thanks

Edit 1:

HTTP filtering was just an example, there is a lot of protocols that I want to filter.

Edit 2:

I tried Scapy, but I don't figure how to filter correctly. The filter only accepts Berkeley Packet Filter expression, i.e., I can't apply a msn, or HTTP, or another specific filter from upper layer. Can anyone help me?

Answer 1

sniff supports a offline option wherein you can provide the pcap file as input. This way you can use the filtering advantages of sniff command on pcap file.

>>> packets = sniff(offline='mypackets.pcap')
>>>
>>> packets
<Sniffed: TCP:17 UDP:0 ICMP:0 Other:0>

Hope that helps !