title: How to run setup/cleanup only in a pytest script, skipping all testcases in it?
body: <p>Having a pytest script that contains the setup/cleanup and various testcases, and I only need to call the setup/cleanup part in it at one time, but need to call some testcases in it at another time.</p>
  <p>So my plan is something like:</p>
  <pre><code>test1.py PYTEST_ADDOPTS=&quot;-k 'not test_abc and not test_def'&quot; SKIP_CLEANUP_ON_SOMETHING=1
  test2.py
  test1.py
  </code></pre>
  <p>Problems is:</p>
  <ol>
  <li>It doesn't work at all because if no testcase could be collected, the entire test script would be omitted, and the setup/cleanup part doesn't have a chance to kick off.</li>
  <li>The <code>PYTEST_ADDOPTS</code> string would become unbearably long when there are more and more testcase functions in <code>test1.py</code>.</li>
  </ol>
  <p>Is there a way to skip all the testcases in <code>test1.py</code>, so that only the setup/cleanup parts would run?</p>