python笔记记录

 

class Test:
    # 类属性
    num = 100

    def __init__(self):
        # 实例属性，其实就像对象中的属性
        self.age = 20

    # def setNum(self, num):
    #     self.num = num
# Test.num=200    print(Test.num)  200
# test_3 =Test()
# test_3.setNum(200)
# print(test_3.num) #200
# print(Test.num)#100

    @classmethod        #类方法
    def setNum(self,num):
        self.num=num

test_4=Test()
test_4.setNum(200)
print(test_4.num)#200
print(Test.num)#200

 

class ShortInputException(Exception):
    '''你定义的异常类'''

    def __init__(self, length, atleast):
        Exception.__init__(self)
        self.length = length
        self.atleast = atleast


try:
    s = input('请输入-->')
    if len(s) < 3:
        raise ShortInputException(len(s), 3)
except EOFError:
    print('/你输入了一个结束标记eof')
except (ShortInputException,s):  # 这个变量绑定到错误的实例
    print('ShortInputException:输入的长度是%d,长度至少应该是%d'%(s.length,s.atleast))
else:
    print('没有异常')