title: python statement with `or` inside square brackets
body: <p>This is a code snippet I pasted from a setup.py python file. I am new to python and don't understand this <code>build_args</code> variable. Could someone give me some explanation for that?</p>
  <pre><code>build_args = [NINJA or MAKE]
  
  # control the number of concurrent jobs
  if self.jobs is not None:
      build_args.extend(['-j', str(self.jobs)])
  
  subprocess.check_call(build_args)
  </code></pre>