重复尝试和例外条款 [英] Repetitive Try and Except Clauses

问题描述

我创建了一堆函数，我需要在所有函数中使用非常相似的 except 子句，但我讨厌在每个函数中使用这么多行 try 和 except 子句以及相同的代码.例如:

导入系统随机导入定义 foo():num=random.random()尝试:如果 num>0.5:打印OK"elif num>0.25: raise NameError('Too Small')否则:引发键盘中断除了名称错误:打印%s 有一个 NameError" % sys._getframe().f_code.co_name除了:打印%s 有一个不同的错误"% sys._getframe().f_code.co_name定义栏():num=random.random()尝试:如果 num>0.8:打印OK"elif num>0.6: raise NameError('Too Small')否则:引发键盘中断除了名称错误:打印%s 有一个 NameError" % sys._getframe().f_code.co_name除了:打印%s 有一个不同的错误"% sys._getframe().f_code.co_name

try"后的代码因函数而异，但except"后的代码相同.我想合并那些 except 语句，这样它们就不会让我的代码看起来如此局促.有什么好的办法吗?

解决方案

Python 装饰器想要.

你说except块总是一样的.制作一个自定义装饰器来做你想做的事.您必须将其应用于每个函数/方法，但它确实可以避免重复.

def handleError(function):定义句柄问题():尝试:功能()除了例外:打印哦不"返回句柄问题@句柄错误定义示例():引发异常(繁荣！")

当调用一个应用了装饰器的方法时:

<前>>>>>>> 示例()哦不>>>

您将需要更改异常类型以及您要执行的操作，但您会明白我要做什么.

I've created a bunch of functions and I need very similar except clauses in all of them, but I hate having so many lines of try and except clauses and the same code inside of each function. For example:

import sys
import random

def foo():
    num=random.random()
    try:
        if num>0.5: print 'OK'
        elif num>0.25: raise NameError('Too Small')
        else: raise KeyboardInterrupt
    except NameError:
        print "%s had a NameError" % sys._getframe().f_code.co_name
    except:
        print "%s had a different Error" % sys._getframe().f_code.co_name

def bar():
    num=random.random()
    try:
        if num>0.8: print 'OK'
        elif num>0.6: raise NameError('Too Small')
        else: raise KeyboardInterrupt
    except NameError:
        print "%s had a NameError" % sys._getframe().f_code.co_name
    except:
        print "%s had a different Error" % sys._getframe().f_code.co_name

The code after "try" is different for the functions, but the code after "except" is the same. I want to consolidate those except statements so they don't make my code look so cramped. Is there a good way to do this?

解决方案

Python Decorators are what you want.

You said the except block is always the same. Make a custom decorator that does what you want. You'll have to apply this to each function/method but it sure does save duplication.

def handleError(function):
    def handleProblems():
        try:
            function()
        except Exception:
            print "Oh noes"
    return handleProblems


@handleError
def example():
   raise Exception("Boom!")

When calling a method with the decorator applied:

>>> 
>>> example()
Oh noes
>>> 

You will need to change the exception types as well as what you do, but you get the jist of where I'm going with this.

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