Response IterableΒΆ

If the last script worked change the return line from:

return [response_body]


return response_body

Then run it again. In an older machine it is possible to notice it is slower. What happens is that the server iterated over the string sending a single byte at a time to the client. So don’t forget to wrap the response in a better performance iterable like a list.

If the iterable yields more than one string the response body length will be the sum of all the string’s lengths like in this script:

#! /usr/bin/env python

from wsgiref.simple_server import make_server

def application(environ, start_response):

    response_body = [
        '%s: %s' % (key, value) for key, value in sorted(environ.items())
    response_body = '\n'.join(response_body)

    # Adding strings to the response body
    response_body = [
        'The Beggining\n',
        '*' * 30 + '\n',
        '\n' + '*' * 30 ,
        '\nThe End'

    # So the content-lenght is the sum of all string's lengths
    content_length = sum([len(s) for s in response_body])

    status = '200 OK'
    response_headers = [
        ('Content-Type', 'text/plain'),
        ('Content-Length', str(content_length))

    start_response(status, response_headers)
    return response_body

httpd = make_server('localhost', 8051, application)

Listening at http://localhost:8051/