http url router

sample.py

from toll import run, Toll

app = Toll(__name__)


@app.route(r'^/$')
def index():
    return 'Hello World'


@app.route(r'^/(\d+)/$')
def showme(num):
    return 'You have posted {}'.format(num), {'Content-Type': 'text/html'}

run('127.0.0.1', 8000, app)

toll.py

import re
from wsgiref.util import setup_testing_defaults
from wsgiref.simple_server import make_server


class NoRouteFoundException(Exception):
    pass


class Toll(object):

    def __init__(self, name):
        self.name = name
        self.routes = {}

    def route(self, pattern):
        def to(action):
            self.routes[pattern] = action
            return action
        return to

    def handle_route(self, path):
        for route, _func in self.routes.items():
            m = re.match(route, path)
            if m:
                # TODO: also set request kwargs somewhere
                # groupdict = m.groupdict()
                return _func(*m.groups())

        raise NoRouteFoundException('No route found')

    def accept(self, environ, res):
        setup_testing_defaults(environ)
        _headers_to_update = {'Content-type': 'text/plain'}
        _headers = {}

        try:
            status = '200 OK'
            result = self.handle_route(environ['PATH_INFO'])
            # would be nice to get rid of this condition
            if type(result) is tuple and len(result) == 2:
                result, _headers = result
        except NoRouteFoundException:
            status = '404 Not Found'
            result = 'ERROR: Not Found'

        _headers_to_update.update(_headers)
        res(status, _headers.items())
        return result


def run(host, port, app):
    httpd = make_server(host, port, app.accept)
    httpd.serve_forever()