You can get unique values by converting the list to a set first:

your_list = [u'hello', u'how', u'how', u'is', u'your', u'life', u'going']

your_set = set(your_list)

print(your_set)

You may covert the set to a list later using your_newlist = list(your_set) in the above code.

Similarly, if you start with a set instead of a list use this code to get unique values:

output = set()

for x in trends:

output.add(x)

print(output)

But remember, sets do not maintain the original order. To know more about the set order visit here:__http://code.activestate.com/recipes/576694/__