error on localhost

when i'm going to login i got the following error

Traceback (most recent call last):
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 3199, in _HandleRequest
    self._Dispatch(dispatcher, self.rfile, outfile, env_dict)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 3142, in _Dispatch
    base_env_dict=env_dict)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 524, in Dispatch
    base_env_dict=base_env_dict)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 2449, in Dispatch
    CGIDispatcher.Dispatch(self, *args, **kwargs)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 2401, in Dispatch
    self._module_dict)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 2438, in curried_exec_cgi
    return ExecuteCGI(*args, **kwargs)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 2309, 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
KeyErr开发者_StackOverflow中文版or: 'warnings'

for this i reinstall the google app engine but not get the result

what to do??

App Engine runs Python 2.5. You need to install Python 2.5 and use that instead of 2.7.