test app for custom predicate docs — https://github.com/Pylons/pyramid/pull/3560

app.ini

[app:main]
use = call:helloapp:main

pyramid.debug_notfound = true
pyramid.debug_routematch = true
pyramid.includes =
    pyramid_debugtoolbar

[server:main]
use = egg:waitress#main
listen = localhost:6455

helloapp.py

from wsgiref.simple_server import make_server

from pyramid.config import Configurator
from pyramid.response import Response


class AnyOfPredicate:
    def __init__(self, val, info):
        self.segment_name = val[0]
        self.allowed = tuple(val[0:])

    def text(self):
        args = (self.segment_name,) + self.allowed
        return "any_of = %s" % (args,)

    phash = text

    def __call__(self, info, request):
        return info["match"][self.segment_name] in self.allowed


class IntegersPredicate:
    def __init__(self, val, info):
        self.segment_names = val

    def text(self):
        return "integers = %s" % (self.segment_names,)

    phash = text

    def __call__(self, info, request):
        match = info["match"]
        for segment_name in self.segment_names:
            match[segment_name] = int(match[segment_name])
        return True


class TwentyTenPredicate:
    def __init__(self, val, info):
        pass

    def text(self):
        return "twenty_ten = True"

    phash = text

    def __call__(self, info, request):
        if info["route"].name in ("ymd", "ym", "y"):
            return info["match"]["year"] == "2010"


def hello_world(request):
    return Response("Hello World!")


def includeme(config):
    # make sure app works
    config.add_route("hello", "/")
    config.add_view(hello_world, route_name="hello")
    # test 1
    config.add_route_predicate("any_of", AnyOfPredicate)
    config.add_route(
        "route_to_num", "/{num}", any_of=("num", "one", "two", "three")
    )
    # test 2
    config.add_route_predicate("integers", IntegersPredicate)
    config.add_route("ymd2", r"/{year:\d+}/{month:\d+}/{day:\d+}",
                     integers=("year", "month", "day"))
    # test 3
    config.add_route_predicate("twenty_ten", TwentyTenPredicate)
    config.add_route("y", "/{year}", twenty_ten=True)
    config.add_route("ym", "/{year}/{month}", twenty_ten=True)
    config.add_route("ymd", "/{year}/{month}/{day}", twenty_ten=True)


def main(global_config, **settings):
    config = Configurator(settings=settings)
    config.include(includeme)
    return config.make_wsgi_app()


if __name__ == "__main__":
    global_config = {}
    settings = {
        "pyramid.debug_notfound": True,
        "pyramid.debug_routematch": True,
    }
    app = main(global_config, **settings)

    server = make_server("localhost", 0, app)
    print(f"Serving helloapp on http://localhost:{server.server_port}/")
    server.serve_forever()

proutes output:

Name                         Pattern                              View                            Method    
----                         -------                              ----                            ------    
hello                        /                                    helloapp.hello_world            *         
route_to_num                 /{num}                               <unknown>                       *         
ymd2                         /{year:\d+}/{month:\d+}/{day:\d+}    <unknown>                       *         
y                            /{year}                              <unknown>                       *         
ym                           /{year}/{month}                      <unknown>                       *         
ymd                          /{year}/{month}/{day}                <unknown>                       *         
debugtoolbar                 /_debug_toolbar/*subpath             <unknown>                       *         
__/_debug_toolbar/static/    /_debug_toolbar/static/*subpath      pyramid_debugtoolbar:static/    *  

Debug toolbar 1:

Debug toolbar 2 (partial):