wx_oauth = WXOAuth()
wx_oauth.init_app(app)

next = request.args.get('next', '/')
redirect_uri = url_for('.authorized', next=next, _external=True)
params = {
    'redirect_uri': redirect_uri,
    'scope': 'snsapi_base',
}
return redirect(wx_oauth.get_authorize_url(**params))