python练习3

import unittest


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


    def get_grade(self):
        if self.score > 100 or self.score < 0:
            raise ValueError
        if self.score >= 80:
            return 'A'
        if self.score >= 60:
            return 'B'
        return 'C'




class TestStudent(unittest.TestCase):


    def test_80_to_100(self):
        s1 = Student('Bart', 80)
        s2 = Student('Lisa', 100)
        self.assertEqual(s1.get_grade(), 'A')#
        self.assertEqual(s2.get_grade(), 'A')


    def test_60_to_80(self):
        s1 = Student('Bart', 60)
        s2 = Student('Lisa', 79)
        self.assertEqual(s1.get_grade(), 'B')
        self.assertEqual(s2.get_grade(), 'B')


    def test_0_to_60(self):
        s1 = Student('Bart', 0)
        s2 = Student('Lisa', 59)
        self.assertEqual(s1.get_grade(), 'C')
        self.assertEqual(s2.get_grade(), 'C')


    def test_invalid(self):
        s1 = Student('Bart', -1)
        s2 = Student('Lisa', 101)
        with self.assertRaises(ValueError):
            s1.get_grade()#
        with self.assertRaises(ValueError):
            s2.get_grade()


if __name__ == '__main__':
    unittest.main()

#编写文档测试
def fact(n):
    '''
    Calculate 1*2*...*n


    >>> fact(1)
    1
    >>> fact(10)
    3628800
    >>> fact(-1)
    Traceback (most recent call last):
        ...
    ValueError
    '''
    if n < 1:
        raise ValueError()
    if n == 1:
        return 1
    return n * fact(n - 1)




if __name__=='__main__':
    import doctest
    doctest.testmod()