title: Splitting of words in pandas DataFrame
body: <p>I have a DataFrame, I wanted to break the text in words, but I am getting a square bracket in between the set of words. I am using the code mentioned below.</p>
  
  <pre><code>for index1, row1 in df.iterrows():
  
     words1 = set([word for word in str(row1.values).split()])
  </code></pre>
  
  <p>I am creating a DataFrame from a CSV file then breaking it into words.</p>
  
  <pre><code>0,"['cell', 'study', 'protein', 'result', 'effect', 'gene', 'treatment', 'may', 'level', 'mouse']"
  </code></pre>
  
  <p>Output--></p>
  
  <pre><code>{'effect', 'result', 'treatment',  'protein', 'may', 'level', 'cell', 'mouse', 'study', 'gene'}
  </code></pre>
  
  <p>but the desired output is </p>
  
  <pre><code>{'effect', 'result', 'treatment', '0', 'protein', 'may', 'level', 'cell', 'mouse', 'study', 'gene'}
  </code></pre>
  
  <p>Why I am getting a list <code>[0', 'protein', 'may', 'level', "'cell", "mouse']</code> in the output?</p>
  
  <p>Please suggest the possible ways to tokenize it.</p>