Jim Lewis \/\/|20+3: > I'm not planning to write C functions. My understanding is that by > using cdefs in the python code one can gain substantial speed. I'm > trying to find a description of how to modify python code in more > detail so it runs fast under pyrex.
I've used pyrex to speed up my code. It worked. While it isn't intended as a tutorial on pyrex you can have a look at it here: http://www.microtonal.co.uk/temper.html The trick is to write C functions using pyrex. That's not much easier than writing C functions in C. But I still found it convenient enough to be worth doing that way. Some tips: - declare functions with cdef - declare the type of every variable you use - don't use Python builtins, or other libraries The point of these rules is that generated C code using Python variables will still be slow. You want Pyrex to write C code using C variables only. To check this is happening you can look at the automatically generated source code to make sure there are no reference counting functions where there shouldn't be. The usual rule for C optimization applies -- rewrite the code that you're spending most time in. But if that innermost function's being called from a loop it can be worth changing the loop as well so that you pass in and out C variables. HTH, Graham -- http://mail.python.org/mailman/listinfo/python-list
