About getattr()

[Duncan Booth]

Leif K-Brooks <eurleif at ecritters.biz> wrote:

>> Why do I still need the getattr() func as below?
>> 
>>>>> print getattr(os.path,"isdir").__doc__
>> Test whether a path is a directory
> 
> You don't.

Correct

> getattr() is only useful when the attribute name is 
> determined at runtime.
> 
getattr() is useful in at least 2 other situations:

maybe you know the attribute name in advance, but don't know whether the 
object has that particular attribute, then the 3 argument form of getattr 
could be appropriate:

   print getattr(x, 'attr', 'some default')

or if the attribute name isn't a valid Python identifier:

   print getattr(x, 'class')