Question

在下面，我有一个try-except块，我想重构它。如你所见，它不是pythonic而且不可维护。

 try:
     try:
         foo()
     except xError:
         doSth()
         raise
 except:
     exc_type = sys.exc_info()[0]
     if exc_type == FooError:
         doBlaBla()
     else:   
         doFlaFla() 

     blablabla()       # whatever the exceptions is, run this code block
     foobar()
     zoo()
     ...

我将该块更改为以下代码;

 try:
     try:
         foo()
     except xError:
         doSth()
         raise
 except FooError:
     doBlaBla()
     raise
 except:
     doFlaFla() 
     raise

     blablabla()       # This is where the problem happens for me.
     foobar()
     zoo()
     ...

正如您所看到的，我需要一个除了 - 最后之类的操作。当没有异常引发但任何异常时它都不会运行。你有什么建议？我应该如何更改这个clode块？

Answer 1

为什么你曾经使用过一次尝试免除块？在我看来，最好把除了语句之外的东西放在一起，这会抓住意想不到的错误。

所以我建议：

try:
    fn()
except Exception1:
    do stuff you want
except Exception 2:
    do another stuff
except Exception as e:
    # Here you will catch an unexpected error, and you can log it
    raise UnknownError -> do stuff you want

Answer 2

您可以将您的异常代码包装在try-finally块中，例如：

try:
    try:
        foo()
    except xError:
        doSth()
        raise
# catch Exception to avoid catching system errors
except Exception as e:
    try:
        if isinstance(e, FooError):
            doBlaBla()
        else:   
            doFlaFla() 
            raise
    finally:
        # this will always run regardless of what you raise

另一种方法可能是这样的：

e = None
try:
    try:
        foo()
    except xError:
        doSth()
        raise
except FooError as e:
    doBlaBla()
except Exception as e:
    doFlaFla() 
    raise
finally:
    # this will always run regardless of what you raise
    if e:
        # exception took place...

Answer 3

为什么不能这样：

def others():
    """Other stuff to do when non-xError occurs.""" 
    blablabla()
    foobar()
    zoo()

然后将因子分解为单个try：

try:
    foo()
except xError:
    doSth()
    raise
except FooError:
    doBlaBla()
    others()
except Exception:
    doFlaFla()
    others()

裸except是usually a bad idea。

Try-except代码块需要优化

3 个答案: