title: How can I efficiently duplicate Django sets?
body: <p>I have a large data set of Course objects in a Django application.</p>
  
  <pre><code>courses = Course.objects.all()
  </code></pre>
  
  <p>I want to make a copy of these courses, except the new courses have different semester values. I have tried this code:</p>
  
  <pre><code>for course in courses:
     newCourse = course
     newCourse.semester = 'Spring 2012'
     newCourse.save()
  </code></pre>
  
  <p>However, this code is not working. It is just changing the semesters of the current courses.</p>
  
  <p>How do I make a copy of the old data set efficiently? Thank you.</p>