title: In pytest, what is the use of conftest.py files?
body: <p>I'm trying to understand what <code>conftest.py</code> files are meant to be used for.</p>
  <p>In my (currently small) test suite I have one <code>conftest.py</code> file at the project root. I use it to define the fixtures that I inject into my tests.</p>
  <p>I have two questions:</p>
  <ol>
  <li>Is this the correct use of <code>conftest.py</code>? Does it have other uses?</li>
  <li>Can I have more than one <code>conftest.py</code> file? When would I want to do that? Examples will be appreciated.</li>
  </ol>
  <p>More generally, how would you define the purpose and correct use of <code>conftest.py</code> file(s) in a pytest test suite?</p>