asyncio byte data transfer

[gary]

I found the below code from my search on the web. The code provides a sample for server implementation using asyncio

import asyncio
async def handle_echo(reader, writer):
    data = await reader.read(100)
    message = data.decode()
    addr = writer.get_extra_info('peername')
    print("Received %r from %r" % (message, addr))
 
    print("Send: %r" % message)
    writer.write(data)
    await writer.drain()
 
    print("Close the client socket")
    writer.close()
 
loop = asyncio.get_event_loop()
coro = asyncio.start_server(handle_echo, 
                            '127.0.0.1', 
                            8888, 
                            loop=loop)
server = loop.run_until_complete(coro)
print('Serving on {}'.format(server.sockets[0].getsockname()))
loop.run_forever()]

Server echoes the data back to the client, but writers.write transmits the data as string. i have a client program written in C that accepts only data format in bytes. How can I change the above program to tansmit bytes instead of string