title: pandas - how to access cell in pandas, equivalent of df[3,4] in R
body: <p>If I have a pandas DataFrame object, how do I simply access a cell?  In R, assuming my data.frame is called df, I can access the 3rd row and 4th column by</p>
  
  <pre><code>df[3,4]
  </code></pre>
  
  <p>What is the equivalent in python?</p>