title: Read each value one by one in a column with respect to another values in another column from a text file
body: <p>For example, I have a text file like this. There are three columns.</p>
  
  <pre><code>data 5 0.1
  data 4 0.2
  data 2 0.3
  data 1 0.5
  </code></pre>
  
  <p>Codes I have:</p>
  
  <pre><code>for line in open("myfile.txt", "r").readlines():
      line = line.split()
      if len(line)&gt;1 and line[0] == 'data':
          time = line[1]
          volume = line[2]
          volume_per_time=float(volume)/float(time)
  print(volume_per_time)
  </code></pre>
  
  <p>I want to print the volume_per_time in a while loop. i.e. I want to call the 3nd column 1st value with respect to 2nd column 1st value. And then one by one with loop function.</p>