PEP 3333: Python Web Server Gateway Interface v1.0.1

This informational PEP clarifies how bytes/text issues are to be handled by the

WGSI protocol. The challenge is that string handling in Python 3 is most

conveniently handled with the :class:`str` type eventhough the HTTP protocol

is itself bytes oriented.

The PEP differentiates so-called *native strings* that are used for

request/response headers and metadata versus *byte strings* which are used for

the bodies of requests and responses.

The *native strings* are always of type :class:`str` but are restricted to code

points between *u0000* through *u00FF* which are translatable to bytes using

*Latin-1* encoding. These strings are used with :func:`start_response` as

response headers or statuses and must follow :rfc:`2616` with respect to

encoding. That is, they must either be *ISO-8859-1* characters or use

:rfc:`2047` MIME encoding.

To make the environment accessible using native strings, the :mod:`wsgiref`

module has a new function, :func:`wsgiref.handlers.read_environ` which

transcodes CGI variables from :attr:`os.environ` into native strings and returns

a new dictionary. This function provides a WSGI native string friendly

abstraction which is especially helpful given that the environment variables are

handled differently on various operating systems (native unicode on Windows or

UTF-8 encoded bytes on some Unix installations).

.. seealso::

:pep:`3333` - Python Web Server Gateway Interface v1.0.1

PEP written by Phillip Eby.