Hi, here's your problem today. This problem was recently asked by AirBNB:

Given a list of words, group the words that are anagrams of each other. (An anagram are words made up of the same letters).

Example:

Input: ['abc', 'bcd', 'cba', 'cbd', 'efg']
Output: [['abc', 'cba'], ['bcd', 'cbd'], ['efg']]

Here's a starting point:

<pre lang=py>
import collections

def groupAnagramWords(strs):
  # Fill this in.

print groupAnagramWords(['abc', 'bcd', 'cba', 'cbd', 'efg'])
# [['efg'], ['bcd', 'cbd'], ['abc', 'cba']]
</pre>