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Debugging difficulty in python with __getattr__, decorated properties and AttributeError.

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Is there any way to raise the original exception that made the call to
__getattr__? I seem to stumble upon a problem where multi-layered attribute
failure gets obscured due to use of __getattr__. Here's a dummy code to
demonstrate my problems:
"""
import traceback


class BackupAlphabet(object):
    pass


class Alphabet(object):
    @property
    def a(self):
        return backupalphabet.a


    def __getattr__(self, name):
        if name == "b":
            return "banana"

        raise AttributeError(
            "'{0} object has no attribute '{1}'"
            .format(self.__class__.__name__, name))


alphabet = Alphabet()
backupalphabet = BackupAlphabet()

print(alphabet.a)
print(alphabet.b)
"""

Running the above code produces this:
"""
Traceback (most recent call last):
  File "example.py", line 26, in <module>
    print(alphabet.a)
  File "example.py", line 20, in __getattr__
    .format(self.__class__.__name__, name))
AttributeError: 'Alphabet object has no attribute 'a'
"""

While it's easy enough to identify the problem here, the traceback is
rather unhelpful in complex situations. Any comments?

Regards,
TB

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Debugging difficulty in python with __getattr__, decorated properties and AttributeError. "Mr. Joe" <titanix88@gmail.com> - 2013-05-03 05:34 +0600
  Re: Debugging difficulty in python with __getattr__, decorated properties and AttributeError. Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-03 00:20 +0000
    Re: Debugging difficulty in python with __getattr__, decorated properties and AttributeError. "Mr. Joe" <titanix88@gmail.com> - 2013-05-03 13:52 +0600
      Re: Debugging difficulty in python with __getattr__, decorated properties and AttributeError. Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-04 06:29 +0000
        Re: Debugging difficulty in python with __getattr__, decorated properties and AttributeError. "Mr. Joe" <titanix88@gmail.com> - 2013-05-14 21:09 +0600
        Re: Debugging difficulty in python with __getattr__, decorated properties and AttributeError. dieter <dieter@handshake.de> - 2013-05-15 08:15 +0200
        Re: Debugging difficulty in python with __getattr__, decorated properties and AttributeError. "Mr. Joe" <titanix88@gmail.com> - 2013-05-15 22:38 +0600
    Re: Debugging difficulty in python with __getattr__, decorated properties and AttributeError. dieter <dieter@handshake.de> - 2013-05-04 07:56 +0200

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