title: Add text to Existing PDF using Python
body: <p>I need to add some extra text to an existing PDF using Python, what is the best way to go about this and what extra modules will I need to install.</p>
  
  <p>Note: Ideally I would like to be able to run this on both Windows and Linux, but at a push Linux only will do.</p>
  
  <p>Edit: <a href="http://pybrary.net/pyPdf/" rel="noreferrer">pyPDF</a> and <a href="https://www.reportlab.com/" rel="noreferrer">ReportLab</a> look good but neither one will allow me to edit an existing PDF, are there any other options?</p>