Sorted Word frequency count using python

Question

I have to count the word frequency in a text using python. I thought of keeping words in a dictionary and having a count for each of these words.

Now if I have to so

Answer 1

You could use Counter and defaultdict in the Python 2.7 collections module in a two-step process. First use Counter to create a dictionary where each word is a key with the associated frequency count. This is fairly trivial.

Secondly defaultdict could be used to create an inverted or reversed dictionary where the keys are the frequency of occurrence and the associated values are lists of the word or words that were encountered that many times. Here's what I mean:

from collections import Counter, defaultdict

wordlist = ['red', 'yellow', 'blue', 'red', 'green', 'blue', 'blue', 'yellow']

# invert a temporary Counter(wordlist) dictionary so keys are
# frequency of occurrence and values are lists the words encountered
freqword = defaultdict(list)
for word, freq in Counter(wordlist).items():
    freqword[freq].append(word)

# print in order of occurrence (with sorted list of words)
for freq in sorted(freqword):
    print('count {}: {}'.format(freq, sorted(freqword[freq])))

Output:

count 1: ['green']
count 2: ['red', 'yellow']
count 3: ['blue']