what is Frame[Ether] and Frame[IP] using scapy in Python?

Hello all,

I am new to Python and I have a couple of questions regarding the code below. I am currently going through a lesson that shows you how to replay packets using scapy. In my try block on the code below, what does "frame[Ether].src" and "frame[IP].src" where did I get these variables from?
Is ".src" a module? what is "[Ether]" and [IP]?

I hope you guys can clarify.

Thank you!

from scapy.all import *
from scapy.utils import rdpcap

src_mac = "08:00:27:ae:6f:d7"
dst_mac = "08:00:27:87:57:be"
src_ip = "192.168.1.118"
dst_ip = "192.168.1.117"

frames = rdpcap("/root/pcaps/ping_traffic.pcap")
for frame in frames:
    try:
        frame[Ether].src = src_mac
        frame[Ether].dst = dst_mac

        if IP in frame:
            frame[IP].src = src_ip
            frame[IP].dst = dst_ip
        sendp(frame)
    except Exception as e:
        print(e)