word_count.py

'''
Created on Mar 19, 2014

Copyright (c) 2014-2015 Dario Bonino
 
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0
 
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License

@author: bonino
'''

import string

def word_count(txt):
    # prepare the words dictionary
    count = {}
    
    # remove characters different from letters and spaces
    txt = txt.lower()
    to_remove = string.punctuation + string.digits + string.whitespace
    
    # remove undesired chars (check if can be done better, e.g., regexp)
    for i in range(0, len(to_remove)):
        txt = txt.replace(to_remove[i], " ")
    
    # split over spaces
    words = txt.split(" ")
    
    # iterate over distinct words
    for word in words:
        
        # strip leading and trailing chars
        key = word.strip()
        
        # filter out empty strings
        if key != '':
            # update the word count
            if (count.get(key, None) != None):
                count[key] = count[key] + 1
            else:
                count[key] = 1
    
    return count


if __name__ == '__main__':
    # main program
    
    # read the filename from the console
    filename = raw_input("Type the filename (absolute or relative path):\n>")
    
    # open the file
    txt_file = open(filename)
    
    # read the file
    text = txt_file.read()
    
    # close the file
    txt_file.close()
    
    # count the words
    count = word_count(text)
    
    # sort the words by ascending letters
    keys = count.keys()
    keys = sorted(keys)
    
    # initialize statistics
    all_words = 0
    (max_word, max_count) = ("", 0)
    
    # show the word counts
    for key in keys:
        print "%s : %d" % (key, count[key])
        all_words += count[key]
        if(max_count < count[key]):
            (max_word, max_count) = (key, count[key])
        
    # show statistics
    print "--------------------------------------------"
    print "Words number: %d" % (all_words)
    print "Unique words: %d" % (len(count))
    print "Most frequent word is: \"%s\"(%d occurrences)" % (max_word, max_count)