python - Is there a wsgi server that will do progressive Transfer-Encoding: chunked -

is there wsgi webserver can progressive transfer-encoding: chunked? i.e. should write content socket received application.

i tried following app wsgiref, waitress, , gunicorn. none of them write 'first bit of content' straight away..

import time  def app(environ, start_response):     start_response('200 ok', [('content-type', 'text/plain')])     def content():         yield 'first bit of content\n'         time.sleep(5)         yield 'second bit of content'     return content() 

thanks tips jon, got working in waitress:

import time   def app(environ, start_response):      start_response('200 ok', [('content-type', 'text/plain')])      def content():         yield ''.join(('first bit of content', '.' * 18000, '\n'))         time.sleep(5)         yield 'second bit of content'     return content()  import waitress waitress.serve(app, host='0.0.0.0', port=8080) 

waitress send data when reaches 18000 bytes (which configurable when create server.)