title: How to access a row in a pandas dataframe with custom index labels?
body: <p>I've created a pandas dataframe to hold the data like so:</p>
  <pre><code>TF_IDF = pd.DataFrame(index = vocab)
  TF_IDF['0'] = 0
  </code></pre>
  <p>where <code>vocab</code> is an array of strings, so the index label of each column is the corresponding string</p>
  <p>so when I print it, it looks like this:</p>
  <pre><code>           0
  life       0
  math       0
  student    0
  experi     0
  control    0
  ...       ..
  slave      0
  linga      0
  31-32      0
  democrat   0
  unsustain  0
  </code></pre>
  <p>How would I access a row at a given index by using a string?</p>
  <p>for example, if I have the string &quot;math&quot; how would one access the value using the index label &quot;math&quot;?</p>