On Tue, Feb 27, 2018 at 11:17 AM, Steven D'Aprano <steve+comp.lang.pyt...@pearwood.info> wrote: > On Tue, 27 Feb 2018 02:09:53 +1100, Chris Angelico wrote: > >> You're still reimplementing the C code in Python, which is inefficient. >> Have you considered going back to the *actual algorithm* and >> implementing that idiomatically in Python? I think you'll find that (a) >> the code is more readable, and (b) the run time is much lower. > > Chris, I think this is incredibly optimistic, if not naive. We're talking > about a PRNG by Marsaglia, so my guess is that the "original algorithm" > *is* the C code. Or possibly Fortran. > > Even if not, even if there is actually a language-neutral algorithm, its > a PRNG which means its going to be filled with bit-twiddling and number- > crunching operations. Pure Python without a JIT is never going to be > competitive with C or Fortran for code like that. >
I may have been a little unclear. It's highly unlikely that the run time of the properly-implemented Python code will be lower than the original C or Fortran. But it most certainly CAN be more efficient than the Python reimplementation of the C implementation, which would narrow the gap considerably. Implementing Python idiotically instead of idiomatically gives you suboptimal performance. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
