ico.py

import urllib
from collections import defaultdict

FAVICON_URL = "http://daringfireball.net/graphics/favicon.ico?v=005"

print('Reading %s' % FAVICON_URL)
icon_bytes = urllib.urlopen(FAVICON_URL).read()

freq = defaultdict(int)
for byte in icon_bytes:
    freq[ord(byte)] += 1

freq = tuple(reversed(sorted( (count, byte) for (byte, count) in freq.items() )))

print('')
print('Bytes   Frequency')
print('-----------------')
print('Total   %d' % len(icon_bytes))
for (count, byte) in freq[:10]:
    print('%02X      %d' % (byte, count))

stdout

Reading http://daringfireball.net/graphics/favicon.ico?v=005

Byte    Frequency
-----------------------
Total   6518
00      2169
FF      896
5A      621
52      621
4A      617
F1      426
01      77
06      40
2A      32
2D      29