title: How can I explicitly free memory in Python?
body: <p>I wrote a Python program that acts on a large input file to create a few million objects representing triangles.  The algorithm is:</p>
  
  <ol>
  <li>read an input file</li>
  <li>process the file and create a list of triangles, represented by their vertices</li>
  <li>output the vertices in the OFF format: a list of vertices followed by a list of triangles.  The triangles are represented by indices into the list of vertices</li>
  </ol>
  
  <p>The requirement of OFF that I print out the complete list of vertices before I print out the triangles means that I have to hold the list of triangles in memory before I write the output to file.  In the meanwhile I'm getting memory errors because of the sizes of the lists.  </p>
  
  <p>What is the best way to tell Python that I no longer need some of the data, and it can be freed?</p>