[Zope-dev] Re: hasattr implementation for Zope?

[Paul Winkler]

On Fri, May 27, 2005 at 11:49:03AM -0400, Jim Fulton wrote:
> BTW, I prefer to code things like this in the following way:
> 
>   def safe_hasattr():
>       marker = object()
> 
>       def safe_hasattr(obj, attr):
>           return getattr(obj, attr, marker) is not marker
> 
>       return safe_hasattr
> 
>   safe_hasattr = safe_hasattr()
>
> This way, there aren't any extra arguments or funny
> globals to confuse matters.  (I've seen code that broke
> because people tried to reuse marker definitions accross
> modules.

Interesting hack. It gets rid of the extra arguments and globals
all right, but it also makes the source a bit less obvious to read.
Does this play nicely with documentation extraction?
AFAICS the docstring must be given on the inner function definition.
 
-- 

Paul Winkler
http://www.slinkp.com