On Tue, 29 Mar 2005 09:09:37 -0500, Charles Hartman <[EMAIL PROTECTED]> wrote:
>I know the answer to this is going to be "It depends . . .", but I want >to get my mind right. In Fowler's *Refactoring* I read: "Older >languages carried an overhead in subroutine calls, which deterred >people from small methods" (followed by the basic "Extract Method" >advice). In Skip Montanaro's "Python Performance Tips" >(http://manatee.mojam.com/~skip/python/fastpython.html) I read: ". . . >use local variables wherever possible. If the above loop is cast as a >function, append and upper become local variables. Python accesses >local variables much more efficiently than global variables." > >These two pieces of advice imply opposite kinds of code revisions. >Obviously they have different purposes, and both are right at different >times. I wonder if anyone has some wisdom about how to think about when >or how often to do which, how to balance them ultimately, and so on. > >Charles Hartman >Professor of English, Poet in Residence >the Scandroid is at: http://cherry.conncoll.edu/cohar/Programs >http://villex.blogspot.com It depends... ;) Converting small functions to inline, usually should only be done in the inner most loops to optimize performance if it's needed. Moving calculations out of those loops by doing them ahead of time is also good. It's good practice in python to put all of your code in functions or class's even if it's a single main() function. def main() (program code) main() Then you avoid the slower globals unless you declare them with the global statement. If main, or any other functions, get too big or complex, split them up as needed. Ron -- http://mail.python.org/mailman/listinfo/python-list
