title: How do I modify the last line of a file?
body: <p>The last line of my file is:</p>
  
  <blockquote>
    <p>29-dez,40,</p>
  </blockquote>
  
  <p>How can I modify that line so that it reads:</p>
  
  <blockquote>
    <p>29-Dez,40,90,100,50</p>
  </blockquote>
  
  <p>Note: I don't want to write a new line. I want to take the same line and put new values after <code>29-Dez,40,</code></p>
  
  <p>I'm new at python. I'm having a lot of trouble manipulating files and for me every example I look at seems difficult.</p>