How to get the content of each layer in Scapy?

Question

I have a pcap file and I can read it with the following code in Python:

from scapy.all import *

packets = rdpcap("mypfile.pcap")

Now I want to read the content of each layer separately like this (the packets are collected from a 6LoWPAN network):

for packet in packets:
    print("Show me layer 2")
    print("Show me layer 3")
    print("Show me layer 4")

Could you please help in this regard as I am new in Scapy?