Maximum recursion depth error in the python function

Question

I am getting maximum recursion depth error in the line if hasattr(self, '_ubuffer'). Can anyone see what am I doing wrong here? Whole code of the function is:

def __getattr__(self, name):
        if hasattr(self, '_ubuffer'):
            buffer = object.__getattribute__(self,'_ubuffer')
            if name in buffer.dtype.names:
                return buffer.data[name]
        return object.__getattribute__(self,name)

Answer 1

hasattr calls __getattr__ which would cause the recursion. From the docs:

hasattr(object, name) The arguments are an object and a string. The result is True if the string is the name of one of the object’s attributes, False if not. (This is implemented by calling getattr(object, name) and seeing whether it raises an exception or not.) [my emphasis]

One way to get around this problem might be to replace if hasattr(self, '_ubuffer') with something like if '_ubuffer' in self.__dict__.

Answer 2

You can use the superclass implementation for regular attribute access:

def __getattr__(self, name):
    try:
        buffer = super(MyClass, self).__getattr__('_ubuffer')
    except AttributeError:
        raise AttributeError('Attribute {} not found.'.format(name))

    if name in buffer.dtype.names:
        return buffer.data[name]
    else:
        raise AttributeError('Attribute {} not found.'.format(name))