Class Failure

Initialize me with an explanation of the error.

By default, this will use the current exception (sys.exc_info()). However, if you want to specify a particular kind of failure, you can pass an exception as an argument.

If no exc_value is passed, then an "original" Failure will be searched for. If the current exception handler that this Failure is being constructed in is handling an exception raised by raiseException, then this Failure will act like the original Failure.

For exc_tb only traceback instances or None are allowed. If None is supplied for exc_value, the value of exc_tb is ignored, otherwise if exc_tb is None, it will be found from execution context (ie, sys.exc_info).

Trap this failure if its type is in a predetermined list.

This allows you to trap a Failure in an error callback. It will be automatically re-raised if it is not a type that you expect.

The reason for having this particular API is because it's very useful in Deferred errback chains:

   def _ebFoo(self, failure):
       r = failure.trap(Spam, Eggs)
       print 'The Failure is due to either Spam or Eggs!'
       if r == Spam:
           print 'Spam did it!'
       elif r == Eggs:
           print 'Eggs did it!'

If the failure is not a Spam or an Eggs, then the Failure will be 'passed on' to the next errback.

Parameters:

• errorTypes (Exception)

Check if this failure's type is in a predetermined list.

Parameters:

• errorTypes (list of Exception classes or fully-qualified class names.)

Returns:

the matching Exception type, or None if no match.

Throw the original exception into the given generator, preserving traceback information if available.

Returns:

The next value yielded from the generator.

Raises:

• StopIteration - If there are no more values in the generator.

Get an object that represents this Failure's stack that can be passed to traceback.extract_tb.

If the original traceback object is still present, return that. If this traceback object has been lost but we still have the information, return a fake traceback object (see _Traceback). If there is no traceback information at all, return None.

__provides__

Value:

<zope.interface.declarations.ClassProvides object at 0xa46b62c>