Get opcode via IDAPython

from idautils import *
from idaapi import *
from idc import *
from binascii import hexlify
 
filename = GetInputFile()
start = MinEA()
end = MaxEA()
cur_addr = start
 
byte_a = bytearray()
byte_s = list()
 
while cur_addr <= end:
    buf = GetManyBytes(cur_addr, ItemSize(cur_addr))
    try:
        byte_a.extend(buf)
        s_buf = hexlify(buf)
        byte_s.append(s_buf)
    except TypeError as e: # type == None
        pass
 
    cur_addr = NextHead(cur_addr, end)
 
with open('opcode_{0}.bin'.format(filename), 'ab') as hxd:
    try:
        hxd.write(byte_a[0:])
    except TypeError as e: # type == None
        pass
 
buf = ''.join(byte_s)
with open('str_opcode_{0}.log'.format(filename), 'a') as shxd:
    try:
        shxd.write(buf)
    except TypeError as e: # type == None
        pass
 

can add to specific list via bytearray.