http://www.reddit.com/r/dailyprogrammer/comments/1e97ob/051313_challenge_125_easy_word_analytics/

word_analytics.py

from __future__ import print_function
from collections import Counter
import re

word_re = re.compile(r"\b[\w-]+\b")
letter_re = re.compile("[a-z]")
symbol_re = re.compile("[^\w\s]")

messages = [
    "Top three most common words: '{0[0][0]}', '{0[1][0]}', '{0[2][0]}'",
    "Top three most common letters: '{0[0][0]}', '{0[1][0]}', '{0[2][0]}'"
]

def analyse(text):
    text = text.lower()
    words = word_re.findall(text)
    word_counter = Counter(words)
    letters = letter_re.findall(text)
    letter_counter = Counter(letters)
    symbols = symbol_re.findall(text)
    
    print(len(words), "words")
    print(len(letters), "letters")
    print(len(symbols), "symbols")
    print(messages[0].format(word_counter.most_common(3)))
    print(messages[1].format(letter_counter.most_common(3)))

if __name__ == "__main__":
    from sys import argv, exit

    if len(argv) < 2:
        print("Usage:", __file__, "<file>")
        exit(0)

    with open(argv[1], "r") as f:
        analyse(f.read())