Michael Tobis <[EMAIL PROTECTED]> wrote: > Still a bit confused actually. Any explanation of the following?
I believe the problem you're having is with WHEN a name is looked up -- which tends to be 'as late as possible, but no later'. > def getf(method,name): > def f(self, *a, **k): return method(self.val, *a, **k) > f.func_name = name > return f Here, 'method' is looked up at each execution of f -- but each instance of f is separate and has a separate closure, so 'method' is what it's worth in THAT call to getf (as desired). > for spec in 'str repr hash hex oct pow add'.split(): > name = '__%s__' % spec > method = getattr(int, name) Here, we're rebinding method in the same scope at each pass; in the end, it's left bound to the last value it had -- the getaddr of 'add' in int. > # comment this out to get the non-working case > > setattr(myint,name,getf(method,name)) # works > > # uncomment three lines to get the non-working case > # raises TypeError: "expected 1 arguments, got 0" at method > invocation > # why isn't this equivalent to the setattr above? Because it's looking up 'method' in the scope of the "def f" -- and in that scope, at the time f executes, the loop is over, so name 'method' is always bound to 'getattr(int, "add")'. > # def f(self, *a, **k): return method(self.val, *a, **k) > > # f.func_name = name > > # setattr(myint,name,f) # doesn't work HTH... Alex -- http://mail.python.org/mailman/listinfo/python-list
