title: Divide slice on slice of the same pandas dataframe
body: <p>Let's say we have</p>
  
  <pre><code>In [0]: df = pd.DataFrame(data={'col1': [1, 2, 3], 'col2': [3, 4, 5]})
  In [1]: df
  Out[2]: 
     col1  col2
  0     1     3
  1     2     4
  2     3     5
  </code></pre>
  
  <p>What I need is to divide <code>df[1:]</code> on <code>df[:-1]</code> and get a dataframe as a result, like this: </p>
  
  <pre><code>Out[3]: 
     col1    col2
  0   2.0    1.3333333333333333
  1   1.5    1.25
  </code></pre>
  
  <p>But of course I'm getting</p>
  
  <pre><code>Out[3]: 
     col1  col2
  0   NaN   NaN
  1   1.0   1.0
  2   NaN   NaN
  </code></pre>
  
  <p>I've tried using <code>iloc</code> for slicing, but got the same result. I'm aware of <code>df.values</code>, but I need a dataframe as a result. Thank you so much.</p>