7stud a écrit : > On Mar 25, 3:09 pm, Steven Bethard <[EMAIL PROTECTED]> wrote: > >>Here's another way of looking at it:: >> >> >>> class Test(object): >> ... pass >> ... >> >>> def greet(): >> ... print 'Hello' >> ... >> >>>>Test.greet = greet >>>>Test.greet >> >> <unbound method Test.greet> > > > Interesting. After playing around with that example a bit and finally > thinking I understood bound v. unbound, I found what appears to be an > anomaly: > ------------ > class Test(object): > pass > > def greet(x): > print "hello" > > Test.func = greet > print Test.func > > t = Test() > print t.func > > def sayBye(x): > print "bye" > > t.bye = sayBye > print t.bye > ------------output: > <unbound method Test.greet> > <bound method Test.greet of <__main__.Test object at 0x6dc50>> > <function sayBye at 0x624b0> > > Why doesn't t.bye cause a method object to be created? >
(technical answer - I leave to some guru the care to explain the motivations for this behaviour) Because t.bye is an attribute of instance t, not of class Test. A descriptor object has to be a class attribute for the descriptor protocol to be invoked. Note that you can override __getattribute__ to change this - but this is somewhat hackish, and will probably slow down things quite a bit. FWIW, if you want to dynamically add a method to an instance: inst.method = func.__get__(inst, inst.__class__) -- http://mail.python.org/mailman/listinfo/python-list
