title: Using readline() in python 3.4
body: <p>I am searching for a keyword say "My system"
  So the readline will search for that keyword and copy the paragraph in which this keyword is present.
  I need to add '#" symbol before every line of the paragraph being printed.
  The code given below gives me just the first line added with "#".</p>
  
  <pre><code>z=open("ABC.txt","r")
  for line in z.readlines():
      if "My system" in line:
          w.write('{}{}'.format('\n"#"',(line)))
  </code></pre>
  
  <p>How can i add "#" before every line of that particular paragraph.
  Please help</p>