title: difference between {str} and {str_} in Python
body: <p>I am trying to debug a code in Python. When I go to debug mode and look at the variable <code>word</code> in a similar code that works fine, I see the type of this variable is shown as <code>{str}</code>, but in the other code that does not work correctly I see the type of <code>word</code> in the debugger is shown as <code>{str_}</code>.
  What is the difference between these and how can I convert a variable type <code>{str_}</code> to a type <code>{str}</code>.</p>
  
  <p>Here is part of the code:</p>
  
  <pre><code>cv = CountVectorizer(min_df=1, charset_error="ignore", stop_words="english", max_features=200)
  counts = cv.fit_transform([text]).toarray().ravel()
  words = np.array(cv.get_feature_names())
  ...
  for word, count in zip(words, counts):
  </code></pre>
  
  <p>I use PyCharm to debug, and it is in Python 3.3.</p>
  
  <p>I appreciate any help on this.</p>