example of dictionary data type

word_occurrence_counter.py

import string
import sys

words = {}
strip = string.whitespace + string.punctuation + string.digits + "\"'"
for filename in sys.argv[1:]:
	for line in open( filename ):
		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 ] ) )