python基础之错误和异常处理

import Exception
# except 在捕获错误异常的时候 是要根据具体的错误类型来捕获的
# 用一个块 可以捕获多个不同类型的异常
# EXception 可以捕获所有异常 当对出现的问题或者错误不确定的情况下 可以使用此种
print(dir(Exception))
try:
    # print(b)  #捕获逻辑的代码
    li=[1,2,3,4]
    print(li[10])
    pass
except NameError as msg:
    # 捕获到的错误 才会在这里执行
    print(msg)
    pass
except IndexError as msg:
    print(msg)
print('初次接触异常')
print('HAHAHAHAHHAHAHAH')

try:
    # print(b)  #捕获逻辑的代码
    # li=[1,2,3,4]
    # print(li[10])
    a=10/0
    pass
except NameError as msg:
    # 捕获到的错误 才会在这里执行
    print(msg)
    pass
except IndexError as msg:
    print(msg)
    pass
except ZeroDivisionError as msg:
    print(msg)
print('初次接触异常')
print('HAHAHAHAHHAHAHAH')

try:
    print(b)  #捕获逻辑的代码
    # li=[1,2,3,4]
    # print(li[10])
    # a=10/0
    pass
# except NameError as msg:
#     # 捕获到的错误 才会在这里执行
#     print(msg)
#     pass
# except IndexError as msg:
#     print(msg)
#     pass
# except ZeroDivisionError as msg:
#     print(msg)
#     pass
except Exception as msg:
    print(msg)
    pass
print('初次接触异常')
print('HAHAHAHAHHAHAHAH')

def A(s):
    return 10/int(s)
    pass
def B(s):
    return A(s)*2
def main():
    try:
        B('0')
        pass
    except Exception as msg:
        print(msg)
        pass
    pass
main()
# 不需要在每个可能出错的地方去捕获,只要在合适的层次去捕获错误就可以了 这样的话 就大大减少我们写try----exception的麻烦
# 异常的抛出机制
#如果在运行时发生异常 解释器会查找相应的异常捕获类型
#如果在当前函数里面没有找到的话 它会将异常传递给上层的调用函数
#如果在最外层 没有找到的话 解释器就会退出 程序down掉

class ToolongmyException(Exception): #自定义异常
    def __init__(self,leng):
        '''
         :param leng:长度
        '''
        self.len=leng
    pass
    def __str__(self):
        return '您输入的数据长度是'+str(self.len)+'已经超过长度了'
    pass
def name_Test():
    name=input('请输入姓名：')
    if len(name)>5:
        raise ToolongmyException(len(name))   #抛出异常
    else:
        print(name)
        pass
    pass
name_Test()

class ToolongmyException(Exception): #自定义异常
    def __init__(self,leng):
        '''
         :param leng:长度
        '''
        self.len=leng
    pass
    def __str__(self):
        return '您输入的数据长度是'+str(self.len)+'已经超过长度了'
    pass
def name_Test():
    name=input('请输入姓名：')
    try:
        if len(name)>5:
            raise ToolongmyException(len(name))   #抛出异常
        else:
            print(name)
            pass
    except ToolongmyException as result:
        print(result)
        pass
    finally:
        print('执行完毕了')
    pass
name_Test()