title: Advanced array/dataframe slicing (numpy/pandas)
body: <p>I'm trying to generate 50 random samples of 30 continuous day periods from a list of corn prices (which is index by date).</p>
  
  <p>So far I've got 'select 50 random days' on line one. For the second line, what I really want is an array of dataframes, each one containing 30 days from sample date. Currently it just returns the price on that day.</p>
  
  <pre><code>samples=np.random.choice(corn[:'1981'].index,50)
  corn['Open'][samples] #line I need to fix
  </code></pre>
  
  <p>What's the cleanest way of doing that?</p>