运行脚本报错：“NameError: name 'driver' is not defined”

[qq_33220373]

代码如下：


运行脚本，为什报图所示错误，新手，希望有人能帮忙解答下

[nieoding]

######################################### ## global

global driver

class MyClass():
    def test(self):
        global driver
        driver = 123
    def test2(self):
        global driver
        print driver
        
        
a = MyClass()
a.test()
a.test2()

############################################ ## self

class MyClass():
    def test(self):
        self.driver = 123
    def test2(self):
        print self.driver
        
        
a = MyClass()
a.test()
a.test2()