simple character frequency with python

#!/usr/bin/env python
import sys
import codecs
sys.stdout = codecs.getwriter('utf-8')(sys.stdout)

content = open(sys.argv[1],'rU').read().decode('utf-8')
letters = list(content)

letterfq = {}

for letter in letters:
  if letter in letterfq: letterfq[letter] += 1
  else: letterfq[letter] = 1

byfq = sorted([(v,k) for k,v in letterfq.items()])

for fq, letter in byfq:
  print letter, fq