title: tfidf oucomes are different for the exact same word
body: <p>I'm running tfidf model in python.</p>
  
  <pre><code>texts=[**tokenized words**]
  dictionary = corpora.Dictionary(texts)
  corpus = list(map(dictionary.doc2bow,texts))
  test_model = models.TfidfModel(corpus)
  corpus_tfidf = test_model[corpus]  
  </code></pre>
  
  <p>And it returns the output which gives some patterns of values to the exact same word.
  For example, I chose the word "AAA".</p>
  
  <pre><code>         key          score
  0       "AAA"       1
  2323    "AAA"       0.896502
  4086    "AAA"       0.844922 
  </code></pre>
  
  <p>Why do they have every different value even though they are exact same.</p>