How to return unique words from the text file using Python

Question

How do I return all the unique words from a text file using Python? For example:

I am not a robot

I am a human

Should return:

Answer 1

Using Regex and Set:

import re
words = re.findall('\w+', text.lower())
uniq_words = set(words)

Other way is creating a Dict and inserting the words like keys:

for i in range(len(doc)):
        frase = doc[i].split(" ")
        for palavra in frase:
            if palavra not in dict_word:
                dict_word[palavra] = 1
print dict_word.keys()