List cannot be copied

Question

I am using the sniff() function of Scapy to sniff packet from the ethernet. I store it in a variable called pkt. Later I want to make a copy of the same by appending contents of pkt in another variable buffpkt. Initially I declared both the variables as list but once pkt store the sniff() output it changes its type to instance. Below is the code.

pkt=[]
buffpkt=[]
pkt=sniff(prn=lambda x:x.sprintf("{IP : %IP.src%  %IP.dst%\n\n} "),timeout=5,store=1)
buffpkt=pkt

I want to make a big list of all the packets sniffed by appending the results to buffpkt but I cannot. Any suggestions?

Answer 1

By just assigning one list to another, you just make the first list point to the second list. To copy the list you can use the slicing operator, like this:

buffpkt = pkt[:]

Now buffpkt will be a copy.

Answer 2

Use standard library copy to copy data structures in Python: http://docs.python.org/library/copy.html