App Engine _ah login page not working locally

Whenever i click on the link created by users.create_login_url(), i get an error (shown below). When deployed, the thing works, but doesn't work locally. What is wrong?

Here's the code:

import random
import os

from google.appengine.api import users
from google.appengine.ext import webapp, db
from google.appengine.ext.webapp import util, template
from google.appengine.ext.webapp.util import run_wsgi_app


class MainHandler(webapp.RequestHandler):
    def get(self):
        url = users.create_login_url('/quote')
        link = '<a href="%s">Login</a>' % url
        self.response.out.write(link)

class QuoteHandler(webapp.RequestHandler):
    def get(self):
        self.response.out.write("Quote Handler!")

    def new(self):
        self.response.out.write("New quote")


def main():
    application = webapp.WSGIApplication([(r'/quote/(.*)',QuoteHandler),('/', MainHandler)],
                                         debug=True)
    util.run_wsgi_app(application)


if __name__ == '__main__':
    main()

And here's the error it gives me:

Traceback (most recent call last):
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 3211, in _HandleRequest
    self._Dispatch(dispatcher, self.rf开发者_Go百科ile, outfile, env_dict)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 3154, in _Dispatch
    base_env_dict=env_dict)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 527, in Dispatch
    base_env_dict=base_env_dict)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 2452, in Dispatch
    CGIDispatcher.Dispatch(self, *args, **kwargs)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 2404, in Dispatch
    self._module_dict)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 2441, in curried_exec_cgi
    return ExecuteCGI(*args, **kwargs)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 2312, in ExecuteCGI
    logging.debug('Executing CGI with env:\n%s', pprint.pformat(env))
  File "C:\Python27\lib\pprint.py", line 60, in pformat
    return PrettyPrinter(indent=indent, width=width, depth=depth).pformat(object)
  File "C:\Python27\lib\pprint.py", line 119, in pformat
    self._format(object, sio, 0, 0, {}, 0)
  File "C:\Python27\lib\pprint.py", line 137, in _format
    rep = self._repr(object, context, level - 1)
  File "C:\Python27\lib\pprint.py", line 230, in _repr
    self._depth, level)
  File "C:\Python27\lib\pprint.py", line 242, in format
    return _safe_repr(object, context, maxlevels, level)
  File "C:\Python27\lib\pprint.py", line 284, in _safe_repr
    for k, v in _sorted(object.items()):
  File "C:\Python27\lib\pprint.py", line 75, in _sorted
    with warnings.catch_warnings():
  File "C:\Python27\lib\warnings.py", line 327, in __init__
    self._module = sys.modules['warnings'] if module is None else module
KeyError: 'warnings'

EDIT SDK Version: 1.3.8 Python: 2.7

You are using Python 2.7 that is not supported by Google App Engine (issue here).
You need to downgrade to Python 2.5 to make it work.

I fixed this problem on Fedora 14 w/ Python 2.7 by commenting out the following:

# logging.debug('Executing CGI with env:\n%s', pprint.pformat(env))

on line 2312 of dev_appserver.py located at google_appengine_sdk_dir/google/appengine/tools

Here's the stack trace, where you can see line 2312 was causing the exception to be thrown:

Traceback (most recent call last):
  File "/google_app_sdk/google/appengine/tools/dev_appserver.py", line 3211, in _HandleRequest
    self._Dispatch(dispatcher, self.rfile, outfile, env_dict)
  File "/google_app_sdk/google/appengine/tools/dev_appserver.py", line 3154, in _Dispatch
    base_env_dict=env_dict)
  File "/google_app_sdk/google/appengine/tools/dev_appserver.py", line 527, in Dispatch
    base_env_dict=base_env_dict)
  File "/google_app_sdk/google/appengine/tools/dev_appserver.py", line 2452, in Dispatch
    CGIDispatcher.Dispatch(self, *args, **kwargs)
  File "/google_app_sdk/google/appengine/tools/dev_appserver.py", line 2404, in Dispatch
    self._module_dict)
  File "/google_app_sdk/google/appengine/tools/dev_appserver.py", line 2441, in curried_exec_cgi
    return ExecuteCGI(*args, **kwargs)
  File "/google_app_sdk/google/appengine/tools/dev_appserver.py", line 2312, in ExecuteCGI
    logging.debug('Executing CGI with env:\n%s', pprint.pformat(env))
  File "/usr/lib64/python2.7/pprint.py", line 60, in pformat
    return PrettyPrinter(indent=indent, width=width, depth=depth).pformat(object)
  File "/usr/lib64/python2.7/pprint.py", line 119, in pformat
    self._format(object, sio, 0, 0, {}, 0)
  File "/usr/lib64/python2.7/pprint.py", line 137, in _format
    rep = self._repr(object, context, level - 1)
  File "/usr/lib64/python2.7/pprint.py", line 230, in _repr
    self._depth, level)
  File "/usr/lib64/python2.7/pprint.py", line 242, in format
    return _safe_repr(object, context, maxlevels, level)
  File "/usr/lib64/python2.7/pprint.py", line 284, in _safe_repr
    for k, v in _sorted(object.items()):
  File "/usr/lib64/python2.7/pprint.py", line 75, in _sorted
    with warnings.catch_warnings():
  File "/usr/lib64/python2.7/warnings.py", line 327, in __init__
    self._module = sys.modules['warnings'] if module is None else module
KeyError: 'warnings'

Commenting out that one line seems to make everything work just fine, no other errors and I don't have to downgrade to Python 2.5.

I've seen this problem -- you're running the wrong version of Python locally.

Install Python 2.5 and ths problem should go away -- it did for me.

http://www.python.org/download/releases/2.5.5/