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<ncogh...@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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