wsgi_bytes

import wsgiserver

def application(environ, start_response):
    body_str = 'Hello world!\n'
    body_str_byte = bytes(body_str, 'utf-8')
    status = '200 OK'
    headers = [('Content-type', 'text/plain')]
    start_response(status, headers)
    return [body_byte]


server = wsgiserver.WSGIServer(application)
server.start()