a858 decrypter

import sys
from sympy.mpmath import mp

def get_pi(n):
	mp.dps = (n+1)
	pi = mp.pi
	return str(pi-int(pi))[2:]


f = open("translated.txt", "w")
msg = "".join(sys.argv[1].split())
parse_error = False
pxmin = pxmax = pymin = pymax = 0
for i in range(len(msg) / 4):
	try:
		x = int(msg[i*4:i*4+2],16)
		y = int(msg[i*4+2:i*4+4],16)
	except:
		parse_error = True
		break

	if i == 0:
		pxmin,pxmax = (x,)*2
		pymin,pymax = (y,)*2

	pxmin = x if x < pxmin else pxmin
	pymin = y if y < pymin else pymin
	pxmax = x if x > pxmax else pxmax
	pymax = y if y > pymax else pymax

dim = pxmax * pymax

if (dim != 0):
	print "generating key using %i digits of pi..." % dim
	pi = get_pi(dim)
	key = []
	c = 0
	d = 1
	header = "".join([ str(i % 10) for i in range(0,pxmax + 1) ])
	key.append(header)
	while c < len(pi):
		key.append(str( d % 10 ) + str( pi[c:c+pxmax] ))
		c += pxmax
		d += 1

	dec = ""
	i = 0
	for i in range(len(msg) / 4):
		try:
			x = int(msg[i*4:i*4+2], 16)
			y = int(msg[i*4+2:i*4+4], 16)
		except:
			parse_error = True
			break
		dec += str(key[y][x])


	i = 0
	text = ""
	while i < len(dec):
		if dec[i] == '1':
			num = dec[i:i+3]
			i += 3
		else:
			num = dec[i:i+2]
			i += 2
		text += "%c" % int(num)
	f.write( text )
f.close()