title: randomly choose the files and add it to the data present in another folder
body: <p>i have two folders(<code>DATA1 and DATA2</code>) and inside it there are 3 subfolders(<code>folder1,folder2 and folder3</code>) as shown below :</p>
  <pre><code>DATA1
      folder1/*.txt   contain 5 files
      folder2/*.txt   contain 4 files
      folder3/*.txt   contain 10 files
  
  DATA2
      folder1/*.txt   contain 8 files
      folder2/*.txt   contain 9 files
      folder3/*.txt   contain 10 files
  </code></pre>
  <p>as depicted above, there are various number of files in each subfolders with different names and each file contain two columns data as shown below:</p>
  <pre><code>1 -2.4654174805e+01
  2 -2.3655626297e+01
  3 -2.2654634476e+01
  4 -2.1654865265e+01
  5 -2.0653873444e+01
  6 -1.9654104233e+01
  7 -1.8654333115e+01
  8 -1.7653341293e+01
  9 -1.6654792786e+01
  10 -1.5655022621e+01
  </code></pre>
  <p>I just want add data folder wise by choosing the second columns of files randomly
  I mean any random data(only second column) from <code>DATA2/folder1/*.txt</code> will be added to <code>DATA1/folder1/*.txt</code>(only second column), similarly <code>DATA2/folder2/*.txt</code> will be added to <code>DATA1/folder2/*.txt</code> and so on.</p>
  <p>most importantly, i don't need to disturb the first column value of any folders only manipulations with second column.And finally i want to save the data.</p>
  <p>can anybody suggest solution for the same
  My directory and data structure is attached here
  <a href="https://i.fluffy.cc/2RPrcMxVQ0RXsSW1lzf6vfQ30jgJD8qp.html" rel="nofollow noreferrer">https://i.fluffy.cc/2RPrcMxVQ0RXsSW1lzf6vfQ30jgJD8qp.html</a></p>
  <p>i want to add folder wise data(from DATA2 to DATA1). First of all enter the DATA2/folder1 and randomly chose any file and select its(file) second column(as it consists of two column). Then add the selected second column to the second column of any file present inside DATA1/folder1 and save it to the OUTPUT folder</p>