gistfile1.py

#!/usr/bin/python                                                                                                                                                                                         
from fractions import Fraction

#para comprimir                                                                                                                                                                                           
scheme = {'000':[1111111,'s1'], '001':[1111110,'s2'], '010':[111110,'s3'],
          '011':[11110,'s4'], '100':[1110,'s5'], '101':[110,'s6'],
          '110':[10, 's7'], '111':[0,'s8']}
#archivo de entrada                                                                                                                                                                                       
f = open('entrada.txt', 'r')
file = f.readline().replace("\n", "")
f.close()
#se codifica                                                                                                                                                                                              
temp = ''
compress = ''
compress_1 = ''
for i in file:
    temp = temp + i
    if temp in scheme:
        compress = compress + str(scheme[temp][0])
        compress_1 = compress_1 + scheme[temp][1]
        temp = ''
#para obtener compression ratio                                                                                                                                                                           
num = Fraction(len(file), len(compress)).numerator
den = Fraction(len(file), len(compress)).denominator
print "*****************************************"
print "Archivo original"
print file
print "Tamano %s bits" %len(file)
print "*****************************************"
print "Archivo comprimido"
print compress
print compress_1
print "Tamano %s bits" %len(compress)
print "*****************************************"
print "compression ratio %s/%s" %(num, den)