title: Pandas: access data from dataframe by row and column number
body: <p>I have a simple program made me confused. I read a 3 * 10 data from a csv file, and I want to access a particular data by its row and column number. But it failed, I doun't know why.</p>
  
  <p>matrix.txt:</p>
  
  <pre><code>1,2,3,4,5,6,7,8,9,10
  11,12,13,14,15,16,17,18,19,20
  21,22,23,24,25,26,27,28,29,30
  </code></pre>
  
  <p>Program:</p>
  
  <pre><code>datainput = pd.read_csv('matrix.txt',sep=',', header = None)
  
  inputinfo = datainput.shape ==&gt; 3, 10
  
  print datainput[3][3] =&gt; failed,but it should return 23, 
  </code></pre>
  
  <p>I can not access any data if the column number is equal or greater than 3</p>