#!/usr/bin/env python3
# Copyright (c) 2008-11 Qtrac Ltd. All rights reserved.
# This program or module is free software: you can redistribute it and/or
# modify it under the terms of the GNU General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version. It is provided for educational
# purposes and is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.

import string
import sys

words = {}
strip = string.whitespace + string.punctuation + string.digits + "\"'"
for filename in sys.argv[1:]:
    with open(filename) as file:
        for line in file:
            for word in line.lower().split():
                word = word.strip(strip)
                if len(word) > 2:
                    words[word] = words.get(word, 0) + 1
for word in sorted(words):
    print("'{0}' occurs {1} times".format(word, words[word]))