Michael M.:
> * The C is very fast, Python not.
> * Target: Do optimization, that Python runs nearly like C.
Python can't be fast as C for that kind of programs.
Note that your original C program gives less digits than the Python
program.
Your original takes about ~15.2 s on my PC. The following version (I
have just cleaned it up a bit, probably it can be improved) needs about
~0.7 seconds with Psyco and ~5.7 s without (Psyco compilation time and
Python startup times aren't included, if you include them the timings
are ~0.94 s and ~5.96 s).
Compiled with ShedSkin this program needs ~0.29 s (redirecting the
output to a file, because ShedSkin printing is slow still).
from time import clock
def compute_pi():
pi = []
a = 10000
b = d = e = g = 0
c = 5600
f = [2000] * (c + 4000 + 1)
while c:
d = 0
g = c * 2
b = c
while b > 1:
d += f[b] * a
g -= 1
f[b] = d % g
d = d // g
g -= 1
d *= b
b -= 1
c -= 14
pi.append("%04d" % int(e + d // a))
e = d % a
return "".join(pi)
import psyco; psyco.bind(compute_pi)
start_time = clock()
print compute_pi()
print "Total time elapsed:", round(clock() - start_time, 2), "s"
Bye,
bearophile
--
http://mail.python.org/mailman/listinfo/python-list
