Python处理多个异常

Question

我想以某种方式处理特定的异常,并且通常记录所有其他异常.这就是我所拥有的:

class MyCustomException(Exception): pass


try:
    something()
except MyCustomException:
    something_custom()
except Exception as e:
    #all others
    logging.error("{}".format(e))

问题是甚至MyCustomException会被记录,因为它继承自Exception.我该怎么做才能避免这种情况？

Answer 1

你的代码还发生了什么？

MyCustomException应该在流程到达第二个except子句之前检查和处理

In [1]: def test():
   ...:     try:
   ...:         raise ValueError()
   ...:     except ValueError:
   ...:         print('valueerror')
   ...:     except Exception:
   ...:         print('exception')
   ...:         

In [2]: test()
valueerror

In [3]: issubclass(ValueError,Exception)
Out[3]: True

Answer 2

只会执行第一个匹配的除了块:

class X(Exception): pass

try:
    raise X
except X:
    print 1
except Exception:
    print 2

只打印1.

即使你在except块中引发异常,除了块之外,它不会被其他异常捕获:

class X(Exception): pass

try:
    raise X
except X:
    print 1
    0/0
except Exception:
    print 2

打印1和加注 ZeroDivisionError: integer division or modulo by zero