title: Make a list of all words in pandas dataframe column
body: <p>I have the following dataframe:</p>
  
  <pre><code>df = pd.DataFrame([{'c1':'Hello world'}, {'c1':'Hello all the world'}])
  </code></pre>
  
  <p>I want to make a list with all the the words contained in the column "c1". The resulting list should look like this:</p>
  
  <pre><code>list=['Hello','world','Hello','all','the','world']
  </code></pre>
  
  <p>I thought I could iterate over the rows in the dataframe and for each row loop through the words in "c1" and output the words to a list, but I can't make it work.</p>