python2 ----创建类实例--调试错误

Question

跟着书上例子学习
1.判断输入的名字---------(没问题)
2.判断输入的学校------------(没问题)
3.判断输入的班级 是否在设定之内 -----可以就打印输入---(没问题)
-----但是输出的值超范围就报错 我设定的班级是['k','1','2','3','4','5']
代码截图如下：

控制台显示如下 正确输入没问题 ：

但是控制台输出超出我预设的范围就报错：

手写代码如下：

class Student(object):
    def __init__(self, name="", school="", grade=""):
        if not name:
            name = raw_input('What is the student \'s name?')
        if not school:
            school = raw_input('What is the student \'s school')
        if not grade:
            grade = self.get_gerade()
        self.name = name
        self.school = school
        self.grade = grade
        self.print_student()

    def get_gerade(self):
        while True:
            grade = raw_input('What is the student \'s [k, 1-5]')

            if grade.lower() not in ['k', '1', '2', '3', '4', '5']:
                print 'I \'m sorry, but {} isn\'t valid.'.format(self.grade)
            else:
                return grade

    def print_student(self):
        print 'Name:{}'.format(self.name)
        print 'School:{}'.format(self.school)
        print 'Grade:{}'.format(self.grade)
def main():
    student1 = Student()
    student2 = Student(name='Byron Bale', grade='2', school='Minnieville')

if __name__ == '__main__':
    main()

Answer 1

  def get_gerade(self):
        while True:
            grade = raw_input('What is the student \'s [k, 1-5]')

            if grade.lower() not in ['k', '1', '2', '3', '4', '5']:
                print 'I \'m sorry, but {} isn\'t valid.'.format(grade)  # 这里错了，不是self.grade
            else:
                return grade

Answer 2

在
print 'I 'm sorry, but {} isn't valid.'.format(self.grade)中，self.grade并没有被定义。程序先运行了self.get_gerade()在定义self.grade,所以报错。

另外，熬夜对身体不好哦