https://wx2.qq.com/?&lang=zh_CN

	    /**
	     * 启动二维码登录
	     */
	    function doQrcodeLogin() {
	        loginFactory.getUUID().then(function (uuid) {
	            utilFactory.log('login',uuid);
	            $scope.uuid = uuid;
	            $scope.qrcodeUrl = 'https://login.weixin.qq.com/qrcode/'+ uuid;
	            $scope.code = 0;
	            $scope.isScan = false;
	            $scope.isIPad = utilFactory.isIPad;
	            $scope.isMacOS = utilFactory.isMacOS;
	            $scope.isWindows = utilFactory.isWindows;
	            $scope.lang = utilFactory.queryParser().lang || 'zh_CN';
	
	            var qrcodeLoaded = false;
	            reportService.report(reportService.ReportType.timing,{
	                timing:{
	                    qrcodeStart:Date.now()
	                }
	            });
	            setTimeout(function(){
	                if(!qrcodeLoaded){
	                    reportService.report(reportService.ReportType.picError,{
	                        text:'qrcode can not load',
	                        src:$scope.qrcodeUrl
	                    });
	                }
	            },3000);
	            $scope.qrcodeLoad = function(){
	                qrcodeLoaded = true;
	                reportService.report(reportService.ReportType.timing,{
	                    timing:{
	                        qrcodeEnd:Date.now()
	                    }
	                });
	            };
	            loginFactory.checkLogin(uuid,1).then(checkLoginHandler, function (data){
	                if(!data && window.checkLoginPromise){
	                    $scope.isBrokenNetwork = true;
	                }else{
	                    $scope.isBrokenNetwork = false;
	                }
	            });
	        }, function (code){
	            console.log('get uuid error');
	            if(!code){
	                $scope.isBrokenNetwork = true;
	            }else{
	                $scope.isBrokenNetwork = false;
	            }
	        });
	    }
	

	angular.module('Services')
	.factory('loginFactory', ['$http', '$q','$timeout', 'accountFactory', 'confFactory', 'utilFactory','mmHttp','reportService', function($http, $q, $timeout, accountFactory, confFactory,utilFactory,mmHttp,reportService) {
	    var service = {
	        getUUID: function () {
	            var deferred = $q.defer();
	            window.QRLogin = {};
	            // ie8
	            $.ajax({
	                url: confFactory.API_jsLogin,
	                dataType : "script",
	                timeout : 10000
	            }).done(function() {
	                if(window.QRLogin.code==200){
	                    deferred.resolve(window.QRLogin.uuid);
	                }else{
	                    deferred.reject(window.QRLogin.code);
	                }
	            }).fail(function(){
	                deferred.reject();
	                console.log('get uuid fail.....');
	            });
	            /*$http.jsonp(confFactory.API_jsLogin).success(function(data){
	                //not standard jsonp, call error handler.
	            }).error(function(data){
	                if(window.QRLogin.code==200){
	                    deferred.resolve(window.QRLogin.uuid);
	                }else{
	                    deferred.reject(window.QRLogin.code);
	                }
	            });*/
	            return deferred.promise;
	        },
	        getQrcode: function (argument) {
	            // body...
	        },

def like_wx_uuid(random_digit=12, reserved_digit=2):
    '''
    微信网页版 https://wx.qq.com/

    https://res.wx.qq.com/a/wx_fed/webwx/res/static/js/index_c7d281c.js https://res.wx.qq.com/a/wx_fed/webwx/res/static/js/index_c7d281c.js
        getUUID: function () {
            var deferred = $q.defer();
            window.QRLogin = {};
            // ie8
            $.ajax({
                url: confFactory.API_jsLogin,
                dataType : "script",
                timeout : 10000
            }).done(function() {
                if(window.QRLogin.code==200){
                    deferred.resolve(window.QRLogin.uuid);
                }else{
                    deferred.reject(window.QRLogin.code);
                }
            }).fail(function(){
                deferred.reject();
                console.log('get uuid fail.....');
            });
            /*$http.jsonp(confFactory.API_jsLogin).success(function(data){
                //not standard jsonp, call error handler.
            }).error(function(data){
                if(window.QRLogin.code==200){
                    deferred.resolve(window.QRLogin.uuid);
                }else{
                    deferred.reject(window.QRLogin.code);
                }
            });*/
            return deferred.promise;
        },


e.g.
wbJM5_KqQw==
oYN1ZHR-Tw==
Yf-wiqev-g==

app.
https://login.weixin.qq.com/qrcode/Yf-wiqev-g==
    '''

    assert random_digit > reserved_digit
    import random, string
    pool = string.ascii_letters + '-_' + string.digits
    return ''.join(random.choice(pool) if i < random_digit - reserved_digit else '=' for i in range(random_digit))