How can I define __getattr__ to operate on all items of container and pass arguments?
Jeremy
jlconlin at gmail.com
Thu Feb 24 16:33:49 EST 2011
On Tuesday, February 15, 2011 2:58:11 PM UTC-7, Jeremy wrote:
>
> > So the arguments haven't yet been passed when __getattr__() is
> > invoked. Instead, you must return a function from __getattr__(); this
> > function will then get called with the arguments. Thus (untested):
> >
> > def __getattr__(self, name):
> > def _multiplexed(*args, **kwargs):
> > return [getattr(item, name)(*args, **kwargs) for item in self.items]
> > return _multiplexed
>
Sorry to resurrect an old(ish) thread, but I have found a problem with this approach. Defining __getattr__ in this manner allows me to access methods of the contained objects---this was the original goal. But it has introduced a problem that I can no longer access the documentation for my class. The error I get is copied below. It seems like the help function is trying to access an attribute of the class, but can no longer get it. Any suggestions:
Thanks,
Jeremy
/home/jlconlin/CustomPython/trunk/Collect.py in <module>()
----> 1
2
3
4
5
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site.pyc in __call__(self, *args, **kwds)
455 def __call__(self, *args, **kwds):
456 import pydoc
--> 457 return pydoc.help(*args, **kwds)
458
459 def sethelper():
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pydoc.pyc in __call__(self, request)
1721 def __call__(self, request=None):
1722 if request is not None:
-> 1723 self.help(request)
1724 else:
1725 self.intro()
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pydoc.pyc in help(self, request)
1768 elif request: doc(request, 'Help on %s:')
1769 elif isinstance(request, Helper): self()
-> 1770 else: doc(request, 'Help on %s:')
1771 self.output.write('\n')
1772
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pydoc.pyc in doc(thing, title, forceload)
1506 """Display text documentation, given an object or a path to an object."""
1507 try:
-> 1508 pager(render_doc(thing, title, forceload))
1509 except (ImportError, ErrorDuringImport), value:
1510 print value
l/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pydoc.pyc in render_doc(thing, title, forceload)
1483 desc = describe(object)
1484 module = inspect.getmodule(object)
-> 1485 if name and '.' in name:
1486 desc += ' in ' + name[:name.rfind('.')]
1487 elif module and module is not object:
TypeError: argument of type 'function' is not iterable
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