On May 6, 5:17 am, "Diez B. Roggisch" <[EMAIL PROTECTED]> wrote: > wyleu wrote: > > I'm trying to supply parameters to a function that is called at a > > later time as in the code below: > > > llist = [] > > > for item in range(5): > > llist.append(lambda: func(item)) > > > def func(item): > > print item > > > for thing in llist: > > thing() > > > which produces the result > > > IDLE 1.2.1 > >>>> ================================ RESTART > >>>> ================================ > > > <function <lambda> at 0xb716356c> > > <function <lambda> at 0xb71635a4> > > <function <lambda> at 0xb71635dc> > > <function <lambda> at 0xb7163614> > > <function <lambda> at 0xb716364c> > >>>> ================================ RESTART > >>>> ================================ > > > 4 > > 4 > > 4 > > 4 > > 4 > > > How can one allocate a different parameter to each instance of the > > function rather than all of them getting the final value of the loop? > > That's a FAQ. Python creates a closure for you that will retain the last > value bound. To prevent that, you need to create a named paramter like > this: > > lambda item=item: func(item) > > That will bind the current item value at the lambda creation time. > > Diez- Hide quoted text - > > - Show quoted text -
I am getting lambda creation-time bindings on 2.5. >>> g= [ lambda h= i: h for i in range( 10 ) ] >>> [ e( ) for e in g ] [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] >>> g= [ lambda: i for i in range( 10 ) ] >>> [ e( ) for e in g ] [9, 9, 9, 9, 9, 9, 9, 9, 9, 9] -- http://mail.python.org/mailman/listinfo/python-list
