1 class MyException(Exception): 2     """ 3     自定义异常,继承Exception 4     """ 5     def __init__(self, msg): 6         self.msg = msg 7  8     def __str__(self): 9         """10         当实例化对象后,print对象将打印该值11         """12         return self.msg13 14 myexception = MyException15 try:16 17     num1 = input("num1:")18     num2 = input("num2")19     num1 = int(num1)20     num2 = int(num2)21     result = num1 + num222     print(result)23     raise myexception("yes. it's ok")24 except ValueError as v:25     print("value error", v)26 except myexception as e:27     print(e)28 except KeyboardInterrupt:29     print("上面无法抓住终止")30 except InterruptedError:31     print("test")32 except SyntaxError:33     print("该异常无法捕获")34 except IndentationError:35     print("该异常依然无法捕获")36 except Exception:37     print("no")38 else:39     print("一般测试用例,或者安装,可以使用,比如安装成功,没有错误")40 finally:41     print("不管前面什么错,最终都会执行这里,除了语法,缩进以外")

 

 

断言

 

断言一般用于条件匹配，如果条件不满足，则不会进行下去，除非刻意去捕获处理

1 a = ["1", "2", "3"]2 filter_a = filter(lambda i: int(i) < 2, a)3 print(list(filter_a))4 try:5     assert len(list(filter_a)) == len(a)6     7 except AssertionError:8     print("条件不匹配,")