A terrible binary number printer

ebin

#!/usr/bin/python
import sys
from ast import literal_eval
if len(sys.argv) != 2:
    print "Usage: ebin INTEGER"
    sys.exit(1)
s = "{0:08b}".format(literal_eval(sys.argv[1]))
n = 4 # split into 4 bit blocks
# awful reversing hack to get proper formatting
s = s[::-1] 
parts = [s[i:i+n] for i in range(0, len(s), n)]
parts = [x[::-1] for x in parts]
print " ".join(parts[::-1])