[Tutor] decorators, __call__ (able) objects

[vince spicer]

agreed much better description, thanks

On Wed, Jul 15, 2009 at 1:02 PM, wesley chun <wescpy at gmail.com> wrote:

> >>> > Can some one give, or point to some good examples of how @decorators
> >>> > work, and __call__ (able) objects?
> >
> > simple example of calling a class
> >
> > class myKlass(object):
> >
> >     def __call__(self, *args, **kws):
> >          print "i was called"
> >
> > >>> test = myKlass()
> > >>> test()
> > i was called
>
>
> close. the example was right, but the description wasn't accurate...
> you meant, "calling an instance." i'm going to plagarize and rip this
> right out of section 14.1.4 from "Core Python Programming:"
>
> "Python provides the __call__() special method for classes, which allows a
> programmer to create objects (instances) that are callable. By default, the
> __call__() method is not implemented, meaning that most instances are
> not callable. However, if this method is overridden in a class definition,
> instances of such a class are made callable. Calling such instance objects
> is
> equivalent to invoking the __call__() method. Naturally, any arguments
> given in the instance call are passed as arguments to __call__()."
>
> as far as decorators go, kent's tutorial is great place to start. here
> are 2 more articles plus PEP 318, where they were defined:
>
> http://www.ibm.com/developerworks/linux/library/l-cpdecor.html
> http://www.artima.com/weblogs/viewpost.jsp?thread=240808
> http://www.python.org/dev/peps/pep-0318
>
> in addition, i devoted section 11.3.6 of Core Python to decorators.
>
> finally, it should be mentioned that starting in 2.6, you can now
> decorate *classes*, as seen here in PEP 3129:
>
> http://www.python.org/dev/peps/pep-3129/
>
> hope this helps!
> -- wesley
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
> "Core Python Programming", Prentice Hall, (c)2007,2001
> "Python Fundamentals", Prentice Hall, (c)2009
>    http://corepython.com
>
> wesley.j.chun :: wescpy-at-gmail.com
> python training and technical consulting
> cyberweb.consulting : silicon valley, ca
> http://cyberwebconsulting.com
>
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