title: split / manipulate pandas column
body: <p>i need help ... I have folowing column <code>abcdefghi</code> or <code>abcdefghijkl</code> or <code>abcdefghijklmno</code>
  I need following output: <code>abc-def def-ghi</code> or <code>abc-def def-ghi ghi-jkl</code> or <code>abc-def def-ghi ghi-jkl jkl-mno</code></p>
  <p>to split the column I use :</p>
  <pre><code>def split_chunk(txt, n=3):
      return [txt[i:i+n] for i in range(0, len(txt), n)]
  
  df=pd.DataFrame(df.COLUMN.apply(split_chunk).to_list())
  </code></pre>
  <pre><code>    1   2   3   4   5
  0   abc def ghi
  1   abc def ghi jkl
  2   abc def ghi jkl
  3   abc def ghi jkl mno
  4   abc def ghi
  5   abc def ghi
  </code></pre>
  <p>to receive multiple columns with my split value ... how can I merge this to my desired output?</p>
  <pre><code>0   abc-def     def-ghi
  1   abc-def     def-ghi     ghi-jkl
  2   abc-def     def-ghi     ghi-jkl
  3   abc-def     def-ghi     ghi-jkl     jkl-mno
  4   abc-def     def-ghi
  5   abc-def     def-ghi
  </code></pre>