Counting the number of unique words in a document with Python

Question

I am Python newbie trying to understand the answer given here to the question of counting unique words in a document. The answer is:

print len(set(w.lower()         


        

Answer 1

You can calculate the number of items in a set, list or tuple all the same with len(my_set) or len(my_list).

Edit: Calculating the numbers of times a word is used, is something different.
Here the obvious approach:

count = {}
for w in open('filename.dat').read().split():
    if w in count:
        count[w] += 1
    else:
        count[w] = 1
for word, times in count.items():
    print "%s was found %d times" % (word, times)

If you want to avoid the if-clause, you can look at collections.defaultdict.