On 24/08/2010 08:40, Michael Foord wrote:
On 24/08/2010 01:25, Nick Coghlan wrote:
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)
This doesn't correctly handle the case where obj is a type object or obj uses __slots__.
If I have time (currently on vacation with only intermittent internet access) I'll provide an update.
I managed an updated version (with tests) during the flight home last night. I've attached it to issue 9732, along with a discussion of the caveats and ways of breaking it: http://bugs.python.org/issue9732 Michael
Michael
Cheers, Nick.
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