class Student(object):
	def __init__(self, name, gender):
		self.name = name
		self.__gender = gender

	def get_gender(self):
		return self.__gender
	def set_gender(self, new_gender):
		self.__gender = new_gender
		return self.__gender

bart = Student('Bart', 'male')
if bart.get_gender() != 'male':
	print('测试失败!')
else:
	bart.set_gender('female')
	if bart.get_gender() != 'female':
		print('测试失败!')
	else:
		print('测试成功!')