In article <mailman.346.1314100765.27778.python-l...@python.org>, smith jack <thinke...@gmail.com> wrote:
> i have heard that function invocation in python is expensive, but make > lots of functions are a good design habit in many other languages, so > is there any principle when writing python function? > for example, how many lines should form a function? Enough lines to do what the function needs to do, but no more. Seriously, break up your program into functions based on logical groupings, and whatever makes your code easiest to understand. When you're all done, if your program is too slow, run it under the profiler. Use the profiling results to indicate which parts need improvement. It's very unlikely that function call overhead will be a significant issue. Don't worry about stuff like that unless the profiler shows its a bottleneck. Don't try to guess what's slow. My guesses are almost always wrong. Yours will be too. If your program runs fast enough as it is, don't even bother with the profiler. Be happy that you've got something useful and move on to the next thing you've got to do. -- http://mail.python.org/mailman/listinfo/python-list
