Inverting a dictionary when some of the original values are identical

Question

Say I have a dictionary called word_counter_dictionary that counts how many words are in the document in the form {\'word\' : number}. For example,

Answer 1

Python dicts do NOT allow repeated keys, so you can't use a simple dictionary to store multiple elements with the same key (1 in your case). For your example, I'd rather have a list as the value of your inverted dictionary, and store in that list the words that share the number of appearances, like:

inverted_dictionary = {}
for key in word_counter_dictionary:
    new_key = word_counter_dictionary[key]
    if new_key in inverted_dictionary:
        inverted_dictionary[new_key].append(key)
    else:
        inverted_dictionary[new_key] = [key]

In order to get the 25 most repeated words, you should iterate through the (sorted) keys in the inverted_dictionary and store the words:

common_words = []
for key in sorted(inverted_dictionary.keys(), reverse=True):
    if len(common_words) < 25:
        common_words.extend(inverted_dictionary[key])
    else: 
        break

common_words = common_words[:25] # In case there are more than 25 words