Decimal to pinary conversion

pinary.py

"""Convert decimal numbers to pinary (base pi).

Fractional and even irrational bases are possible, but aren't really useful for
anything. Base pi has four digits: 0, 1, 2, and 3. What's interesting is that
there's some "space" between the highest digit and the base, which means that
there are numbers with multiple valid representations. You'll notice:

  decimal 7.000000 = pinary 20.2021120021
  decimal 8.000000 = pinary 21.2021120021
  decimal 9.000000 = pinary 22.2021120021
  decimal 10.000000 = pinary 100.0102212222

Wait, what about pinary 23.202..? That's also equal to 10. What about 30(pi),
31(pi), etc? Well, 31(pi) is 10.424, which is greater than 100(pi). Both 32(pi)
and 33(pi) are also greater than 100(pi).

A fun thought experiment, but not very useful otherwise.
"""

import math
import sys

val = float(sys.argv[1])
try:
  digits = int(sys.argv[2])
except:
  digits = 5

sys.stdout.write('decimal %f = pinary ' % val)

# The highest max digit needed is log_pi(val)
for place in range(int(math.log(val, math.pi)), -digits-1, -1):
  place_val = math.pow(math.pi, place)
  digit = math.floor(val / place_val)
  assert digit <= 3
  val -= (place_val * digit)
  sys.stdout.write('%d' % digit)
  if place == 0:
    sys.stdout.write('.')

print ''

Just what I was looking for. Awesome.