Re: [Python-Dev] 'hasattr' is broken by design

On Tue, Aug 24, 2010 at 8:15 AM, Nick Coghlan ncoghlan@gmail.com wrote:

Now, it may be worth considering an addition to the inspect module that was basically:

def getattr_static(obj, attr):    """Retrieve attributes without triggering dynamic lookup via the descriptor protocol,        __getattr__ or __getattribute__.

Note: this function may not be able to retrieve all attributes reported by dir(obj)    """    try:        instance_dict = object.__getattribute__(obj, "__dict__")    except AttributeError:        pass    else:        if attr in instance_dict:            return instance_dict[attr]    for entry in getmro(obj.__class__):        try:            return entry.__dict__[attr]        except AttributeError:            pass

Second attempt with a default value parameter and correctly raising AttributeError if not found:

_sentinel = object() def getattr_static(obj, attr, default=_sentinel): """Retrieve attributes without triggering dynamic lookup via the descriptor protocol, __getattr__ or __getattribute__.

Note: this function may not be able to retrieve all attributes reported by dir(obj) """ try: instance_dict = object.__getattribute__(obj, "__dict__") except AttributeError: pass else: if attr in instance_dict: return instance_dict[attr] for entry in getmro(obj.__class__): try: return entry.__dict__[attr] except AttributeError: pass if default is not _sentinel: return default raise AttributeError(attr)

Cheers, Nick.