python count number of unique elements in a list

1# Basic syntax:
2len(set(my_list))
3# By definition, sets only contain unique elements, so when the list
4# is converted to a set all duplicates are removed. 
5
6# Example usage:
7my_list = ['so', 'so', 'so', 'many', 'duplicated', 'words']
8len(set(my_list))
9--> 4
10
11# Note, list(set(my_list)) is a useful way to return a list containing
12#	only the unique elements in my_list

1len(set(["word1", "word1", "word2", "word3"]))
2# set is like a list but it removes duplicates
3# len counts the number of things inside the set