New-style classes and special methods

Jack Diederich jack at performancedrivers.com
Mon Feb 24 08:45:07 CET 2003


On Mon, Feb 24, 2003 at 06:38:57PM +1100, Andrew Bennetts wrote:
> On Mon, Feb 24, 2003 at 07:13:44AM +0000, Carl Banks wrote:
> > Jp Calderone wrote:
> > > [-- text/plain, encoding quoted-printable, 37 lines --]
> > > 
> > >  Consider this class:
> > > 
> > >    class Foo:
> > >        def __getattr__(self, name):
> > >            return lambda arg: arg
> > > 
> > >  It can be used thusly:
> > > 
> > >    f = Foo()
> > >    print f[10]
> > 
> > Sure?
> 
> Yep, I'd say he's sure.
> 
Confused me at first, too

class Foo:
  def __getattr__(self, name):
    print name
    return lambda x:x

f = Foo()
f[10]

prints
'__getitem__'

So writing it without the obfu

class Foo:
  def __getitem__(self, name):
    return name

An aside, don't try 'print self' above, it tries to get __repr__
for the class ... 

IMO the newer behavior makes more sense; python wasn't meant
to provide you impossible questions to ask at interviews

-jackdied








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