title: How to insert strings from one column of pandas DataFrame to another column at specific index?
body: <p><strong>My problem</strong></p>
  
  <p>We have this array type data as m:</p>
  
  <pre><code>    0   1   2   3
  0   746200.0    IP:aWSrjjB  foldcauchy  foldcauchy(c=3.40, loc=853.32, scale=188436.01)
  1   1061881.5   IP:joW6uH4  johnsonsu   johnsonsu(a=-0.39, b=0.46, loc=715076.10, scale=70401.41)
  2   645000.0    IP:4Q3L2kB  foldcauchy  foldcauchy(c=3.94, loc=835.77, scale=184545.16)
  3   284375.0    IP:WLP1cdn  loglaplace  loglaplace(c=1.81, loc=-1001.33, scale=701001.33)
  4   666600.0    IP:kQn348T  johnsonsu   johnsonsu(a=-0.39, b=0.46, loc=715076.10, scale=70401.41)
  5   754678.5    IP:kQn348T  loglaplace  loglaplace(c=1.93, loc=-1087.33, scale=786087.33)
  </code></pre>
  
  <p>The second column is a unique IP for each row. Its type is str.</p>
  
  <p>The last column is a bunch of distributions for each row. its type is str.</p>
  
  <p>I would like to append the unique IP to the last column.</p>
  
  <hr>
  
  <p><strong>My attempt</strong></p>
  
  <p>I tried using the following code:</p>
  
  <pre><code>V = []
  ([V.append(m[3][1]), V.append(m[1][1])])
  </code></pre>
  
  <p>Yet, that resulted in the wrong output:</p>
  
  <pre><code> ['loglaplace(c=1.88, loc=-932.82, scale=674382.82)',
   'IP:slaL5jw']
  </code></pre>
  
  <p>Although I could use <code>str( ['loglaplace(c=1.88, loc=-932.82, scale=674382.82)',
   'IP:slaL5jw'])</code></p>
  
  <hr>
  
  <p><strong>Example of the desired output:</strong></p>
  
  <pre><code>   0   1   2   3
  0   746200.0    IP:aWSrjjB  foldcauchy  foldcauchy(c=3.40, loc=853.32, scale=188436.01, IP:aWSrjjB)
  1   1061881.5   IP:joW6uH4  johnsonsu   johnsonsu(a=-0.39, b=0.46, loc=715076.10, scale=70401.41, IP:joW6uH4)
  </code></pre>