Characters frequency counting utility, handy when it boils down to Al-Kindi cryptanalysis.

CharFreqs.py

# Prints out characters occurences frequency
# This can be used in Al-Kindi related cryptographic
# analysis

from sys import argv
import operator

text = ""
occurs = {}
freqs = {}

print "Characters frequency counter v0.1"

for a in range(256):
	freqs[`a`] = 0.
	occurs[`a`] = 0

if len(argv) == 1: text = raw_input("Input text to analyse:\n")
else: text = open(argv[1]).read()

for a in text: occurs[`ord(a)`] += 1

for a in range(256):
	freqs[`a`] = (float(occurs[`a`]) / len(text)) * 100

print "\n[+] Input text length:", len(text), "\n"

f = reversed(sorted(freqs.iteritems(), key=operator.itemgetter(1)))
n=0
for k, v in f:
	if occurs[k] == 0: continue
	else: n+=1

	c = chr(int(k))
	if int(k) < 0x20: c = ''

	print "%03d (%02Xh) '%s'; occurs: %d; freq: %.3f%%" \
			% (int(k), int(k), c, occurs[k], v)

print "\n[+] In total occured %d unique characters." % n