title: Indexing a pandas dataframe by integer
body: <p>I can't seem to find an elegant way to <a href="http://pandas.pydata.org/pandas-docs/stable/indexing.html" rel="nofollow noreferrer">index</a> a <a href="http://pandas.pydata.org/pandas-docs/stable/dsintro.html" rel="nofollow noreferrer"><code>pandas.DataFrame</code></a> by an integer index.
  In the following example I want to get the value 'a' from the first element of the <code>'A'</code> column. </p>
  
  <pre><code>import pandas
  df = pandas.DataFrame(
      {'A':['a','b', 'c'], 'B':['f', 'g', 'h']}, 
      index=[10,20,30]
      )
  </code></pre>
  
  <p>I would expect <code>df['A'].ix[0]</code> and <code>df['A'][10]</code> both  to return <code>'a'</code>. 
  The <code>df['A'][10]</code> does return <code>'a'</code>, but <code>df['A'].ix[0]</code> throws a <code>KeyError: 0</code>. The only way I could think of to get the value <code>'a'</code> based on the index 0 is to use the following approach. </p>
  
  <pre><code>df['A'][df['A'].index[0]]
  </code></pre>
  
  <p>Is there a shorter way to get <code>'a'</code> out of the dataframe, using the 0 index?</p>
  
  <p><strong>Update</strong></p>
  
  <p>As of pandas 0.11 there is a another way to <a href="http://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-integer" rel="nofollow noreferrer">index by integer</a>.</p>
  
  <pre><code>df.iloc[0] # integer based, gives the first row
  df.loc[10] # label based, gives the row with label 10
  </code></pre>
  
  <p>This <a href="http://pandas.pydata.org/pandas-docs/stable/indexing.html#deprecations" rel="nofollow noreferrer">supersedes</a> the <code>irow</code> approach . </p>