Find Unique Characters in a File

Question

I have a file with 450,000+ rows of entries. Each entry is about 7 characters in length. What I want to know is the unique characters of this file.

For instance, if my f

Answer 1

Python w/sets (quick and dirty)

s = open("data.txt", "r").read()
print "Unique Characters: {%s}" % ''.join(set(s))

Python w/sets (with nicer output)

import re

text = open("data.txt", "r").read().lower()
unique = re.sub('\W, '', ''.join(set(text))) # Ignore non-alphanumeric

print "Unique Characters: {%s}" % unique