title: Combined tokenized words into single list in pandas
body: <p>I have a pandas dataframe with column as 'tokenized_texts':-</p>
  
  <pre><code>Tokenized_texts
  
  [obama,america,counterpart]
  [trump,election]
  [development,china,canada]
  ..................
  .................
  ................
  [football,world,cup]
  </code></pre>
  
  <p>I want to convert it into single list which includes all tokenized words:</p>
  
  <p>Expected output</p>
  
  <pre><code>[obama,america,counterpart,trump,election,development,china,canada,.......,world,cup]
  </code></pre>