title: Remove NaNs from Dataframe?
body: <p>I have the following code:</p>
  
  <pre><code>sample_data = OrderedDict((df.name, df['col'].sample(n=3)) for df in test_cases[1:])
  sample = pd.DataFrame(sample_data)
  </code></pre>
  
  <p>Which gives the following dataframe:</p>
  
  <pre><code>col1   col2
  A      NaN
  P      NaN
  NaN    E
  NaN    R
  U      NaN
  NaN    Y
  </code></pre>
  
  <p>How do I get the following dataframe:</p>
  
  <pre><code> col1   col2
   A      E
   P      R
   U      Y
  </code></pre>