Url bouncer for redirecting svn urls to bitbucket

pypy-bouncer.py

from urlparse import urljoin

from google.appengine.ext import webapp
from google.appengine.ext.webapp import util, WSGIApplication


class Bouncer(webapp.RequestHandler):

    def __init__(self, mapping=()):
        super(Bouncer, self).__init__(self)
        self.mapping = mapping

    @classmethod
    def from_mapping(self, mapping):
        return lambda: Bouncer(mapping)

    def get(self, path):
        newloc, oldbasepath, newbasepath = self.mapping
        newpath = path.replace(oldbasepath, newbasepath)
        newurl = urljoin(newloc, newpath)
        #: Uncomment this line and comment the one below for testing
        # self.response.out.write(newurl)
        self.redirect(newurl, permanent=True)

    def handle_exception(self, exception, debug_mode):
        self.response.out.write(exception)


def main():
    mapping = ("https://bitbucket.org",
               "svn/pypy/trunk",
               "pypy/pypy/src/default")
    application = WSGIApplication(
        [(r'/(.*)', Bouncer.from_mapping(mapping))],
        debug=True)
    util.run_wsgi_app(application)


if __name__ == '__main__':
    main()