I'm trying to attach 3rd party service to my site (payment system). This
service sends information to my Pyramid application at specific URL by POST
requests. This POST request is non-Unicode and data field includes
non-ASCII chars. And such request raises UnicodeDecodeError.

Reproduce such error is easy. Create non-Unicode file and put there
<form action="http://localhost:6543/" method="post">
       <input type="submit" name="button" value="NON-ASCII CHARS HERE">
</form>
then open page in browser and press button.

Even pylonsproject.org return Internal Server Error on such test.

I have already read at ICR #pyramid that malformed request should throw
exception. But as for me it is abnormal when simple HelloWorldApp that not
requires parameters at all have such behavior. Some hacker can use it to
fill out your exception log or mailbox (depending on where your tracebacks
goes).

So... Is there any way to process non-Unicode POST-request inside Pyramid
application?

If you want to continue to treat these requests as errors but suppress
exceptions, it's pretty easy, just register an exception view for
UnicodeDecodeError:

    @view_config(context=UnicodeDecodeError, renderer='string')
    def handle_decode_error(request):
        return 'Sorry, something is not encoded properly'

If, on the other hand, you don't want the request to be treated as an
error, but you want it to be accepted and processed by something, it's
probably possible, but how you do it would depend on the particulars of
the application.  Note that anything that accesses request.POST or
request.params will trigger an attempt at decoding; some Pyramid
predicates do this themselves, and of course if your application does
this, it will trigger the same.  So seeing a traceback in the context of
your particular application would probably be necessary.

- C