failureaction 1.0a1

此包旨在提供在异常情况下执行自定义动作的装饰器。让我们看看一个例子

首先，我们需要一个包含一些方法的对象。我们将这些方法装饰为 PrintOnFailure 装饰器。这个简单的示例装饰器在发生异常时打印给定的消息。

>>> from failureaction import ConflictError
>>> from failureaction import PrintOnFailure
>>> class TestOb(object):
...
...    @PrintOnFailure(msg='Some numeric calculation went wrong!')
...    def divide(self, a, b):
...        return a/b
...
...    @PrintOnFailure()
...    def doraise(self):
...        raise ConflictError

我们有两个方法。一个（除法）执行两个数字的数值除法，另一个引发一个自定义定义的ConflictError。现在让我们看看这些方法的作用

>>> ob = TestOb()
>>> ob.divide(4, 2)
2

>>> ob.divide(42, 0)
Some numeric calculation went wrong!

>>> ob.doraise()
Traceback (most recent call last):
...
ConflictError

模块提供的 ActionOnFailure 装饰器旨在由自定义类覆盖。就像这样

>>> from failureaction import ActionOnFailure
>>> class MailOnFailure(ActionOnFailure):
...
...     def __init__(self, subject):
...         self.subject = subject
...
...     def _doaction(self, context, e):
...         """ send a mail, if an exception was raised """
...         print "Subject:", self.subject
...         print e

>>> class TestOb2(object):
...
...     @MailOnFailure(subject='An error occured')
...     def critical(self):
...         import _not_existent_hopefully_

>>> ob2 = TestOb2()
>>> ob2.critical()
Subject: An error occured
No module named _not_existent_hopefully_