[Python-Dev] Re: About Pyrex (original) (raw)

Greg Ewing greg@cosc.canterbury.ac.nz
Wed, 10 Apr 2002 16:44:42 +1200 (NZST)

I was wondering if you know about Boost.Python: http://www.python.org/sigs/c++-sig/

I had heard of it, but hadn't looked very closely at it. It looks interesting -- you seem to be approaching the problem from exactly the opposite direction, in a way. It's hard to get an idea of how your approach stacks up against mine, because they're so different.

One thing I can say is that yours stands a better chance of coping with C++ in its full generality than mine does at the moment!

In your example you cross the boundary (via a C API call) each time you produce a result. Isn't that in general eliminating much of the gain of using C?

No, because in that example there's a lot of computation going on between each result. The inner loop there isn't the one collecting results, it's the one doing the divisions, which runs entirely in C.

I hope to teach Pyrex more about some of the builtin objects, so, e.g. you could return an array.array of numbers instead of a Python list. But even then, if Python code is to do anything with the individual numbers, they will get converted to Python objects.

In general -- if Python code needs to get at the results, they have to be converted to Python objects somewhere, somehow. I don't see a way around that.

Greg Ewing, Computer Science Dept, +--------------------------------------+ University of Canterbury, | A citizen of NewZealandCorp, a | Christchurch, New Zealand | wholly-owned subsidiary of USA Inc. | greg@cosc.canterbury.ac.nz +--------------------------------------+