Group Anagrams

from collections import defaultdict
class Solution(object):
    def groupAnagrams(self, strs):
        anagram_map=defaultdict(list)
        anagram_list=[]

        for word in strs:
            sorted_tuple=tuple(sorted(word))
            anagram_map[sorted_tuple].append(word)

        for val in anagram_map.values():
            anagram_list.append(val)
        return anagram_list

"""
line 4 and 5: creating empty dictionay and empty list
line 7-9: sorting each words in strs by their character like 
('a', 'e', 't')
('a', 'e', 't')
('a', 'n', 't') ... and
forming dictionaries that have tuple as key and list of anagram words as values.
we use tuple as key coz tuple is immutable. 
dictionaries store unique key values so when it encounters same key as before like tuple of (eat and tea) it 
stores both of them in the same place coz their sorted_tuple value is same.
"""