I wish I had time to dig into your specific problem because it looks interesting. But I think you might want to look at "python generators". I beleive there is no reason that they can't yield a function.
http://www.python.org/peps/pep-0255.html http://docs.python.org/ref/yield.html http://linuxgazette.net/100/pramode.html James On Sunday 03 April 2005 02:12 pm, Brendan wrote: > Hi everyone > > I'm new to Python, so forgive me if the solution to my question should > have been obvious. I have a function, call it F(x), which asks for two > other functions as arguments, say A(x) and B(x). A and B are most > efficiently evaluated at once, since they share much of the same math, > ie, A, B = AB(x), but F wants to call them independantly (it's part of > a third party library, so I can't change this behaviour easily). My > solution is to define a wrapper function FW(x), with two nested > functions, AW(x) and BW(x), which only call AB(x) if x has changed. > > To make this all clear, here is my (failed) attempt: > > #------begin code --------- > > from ThirdPartyLibrary import F > from MyOtherModule import AB > > def FW(x): > lastX = None > aLastX = None > bLastX = None > > def AW(x): > if x != lastX: > lastX = x > # ^ Here's the problem. this doesn't actually > # change FW's lastX, but creates a new, local lastX > > aLastX, bLastX = AB(x) > return aLastX > > def BW(x): > if x != lastX: > lastX = x > # ^ Same problem > > aLastX, bLastX = AB(x) > return bLastX > > #finally, call the third party function and return its result > return F(AW, BW) > > #-------- end code --------- > > OK, here's my problem: How do I best store and change lastX, A(lastX) > and B(lastX) in FW's scope? This seems like it should be easy, but I'm > stuck. Any help would be appreciated! > > -Brendan > -- > Brendan Simons -- James Stroud, Ph.D. UCLA-DOE Institute for Genomics and Proteomics Box 951570 Los Angeles, CA 90095 http://www.jamesstroud.com/ -- http://mail.python.org/mailman/listinfo/python-list
