__getattribute__ and __getattr__

[Gigi]

Hi,
In the Python documentation regarding __getattribute__ (more attribute 
access for new style classes) it is mentioned that if __getattribute__ 
is defined __getattr__ will never be called (unless called explicitely). 
Here is the exact citation:

"""
The following methods only apply to new-style classes.

__getattribute__( 	self, name)
     Called unconditionally to implement attribute accesses for 
instances of the class. If the class also defines __getattr__, it will 
never be called (unless called explicitly). This method should return 
the (computed) attribute value or raise an AttributeError exception. In 
order to avoid infinite recursion in this method, its implementation 
should always call the base class method with the same name to access 
any attributes it needs, for example, "object.__getattribute__(self, 
name)".
"""

I discovered that it is not so for Python 2.3.4 on Windows at least. The 
actual behavior is that if both __getattribute__ and __getattr__ methods 
exist then __getattribute__ is called first, but if it raises 
AttributeError then the exception will be swallowed silently and 
__getattr__ will be invoked. Note that if I forward to the default 
object.__getattribute__ or if I raise the AttributeError myself the 
result is the same. My understanding of the documentation is it that the 
program should just exit with the AttributeError exception.

Here is the code:

class A(object):
     def __getattribute__(self, name):
         return object.__getattribute__(self, name)
	# raise AttributeError()

     def __getattr__(self, name):
         return 42

if __name__ == '__main__':
     a = A()
     print a.x

Here is the Output:

42