average word/line/character count for text files in directory

wordcount.py

#!/usr/bin/env python

import sys, os

DIRECTORY = sys.argv[1]
ARTICLES = 0
LINECOUNT = []
WORDCOUNT = []
CHARACTERCOUNT = []
CONTRAIN_SAMPLE_SIZE = 1000

for subdir, dirs, files in os.walk(DIRECTORY):
	for file in files:
		filepath = subdir + os.sep + file
		if ((filepath.endswith(".txt")) and (ARTICLES < CONTRAIN_SAMPLE_SIZE)):
			#print filepath
			num_lines = 0
			num_words = 0
			num_chars = 0
			try:
				with open(filepath, 'r') as f:
					for line in f:
						words = line.split()
						num_lines += 1
						num_words += len(words)
						num_chars += len(line)
			except:
				print("ERROR OPENING " + file)
			ARTICLES = ARTICLES + 1
			LINECOUNT.append(num_lines)
			WORDCOUNT.append(num_words)
			CHARACTERCOUNT.append(num_chars)
			#print(num_words)

average_words = sum(WORDCOUNT) / float(len(WORDCOUNT))
average_lines = sum(LINECOUNT) / float(len(LINECOUNT))
average_characters = sum(CHARACTERCOUNT) / float(len(CHARACTERCOUNT))
print "ARTICLES ANALYZED : " + str(ARTICLES)
print "AVERAGE WORD COUNT: " + str(int(average_words))
print "AVERAGE LINE COUNT: " + str(int(average_lines))
print "AVERAGE CHAR COUNT: " + str(int(average_characters))