TopCommonWordsInFile

import os
import string
from collections import Counter

class TopCommonWords():
    """
    Class for finding Top common words in any text file
    Each word will be converted to lowercase, and stripped all punctuation, whitespaces, digits, quotes
    """
    STRIP_CHARS=string.whitespace + string.punctuation + string.digits + "\"'"

    def __init__(self, min_word_length=3, common_words_result=10):
        """
        In init will be only some params
        @min_word_length - param, minimum length of word
        @common_words_result - how
        """
        self._filename = None
        self.min_word_length = min_word_length
        self.common_words_result = common_words_result

    @property
    def filename(self):
        """return  previously setted filename or asks user to input filename"""
        if not self._filename:
            filename = raw_input('Please enter filepath to file:\n')
            if os.path.isfile(filename):
                self._filename = filename
                return self._filename
            else:
                raise ValueError("Supllied path %s does not link to file. Exiting.." % filename)
        else:
            return  self._filename

    def getwords(self):
        """Memory efficient iteration thought words in file"""
        for line in open(self.filename):
            for word in line.lower().split():
                word=word.strip(self.STRIP_CHARS)
                if len(word) > self.min_word_length:
                    yield (word)

    def process_file(self):
        """Process file and print results """
        try:
            self.top = Counter(self.getwords())
        except ValueError as e:
            print e.message
        else:
            self.print_results()

    def print_results(self):
        """printing results after processing"""

        print "Top %s results processing %s" % (self.common_words_result, self._filename)
        for each in self.top.most_common(self.common_words_result):
            print each


if __name__ == '__main__':
    top = TopCommonWords()
    top.process_file()