title: 'pytest' exits with no error, but with "collected 0 items"
body: <p>I have been trying to run unit tests using <a href="https://docs.pytest.org/en/stable/" rel="noreferrer">pytest</a> in Python. I had written a module with one class and some methods inside that class. I wrote a unit test for this module (with a simple assert statement to check equality of lists) where I first instantiate the class with a list. Then I invoke a method on that object (from the class). Both <code>test.py</code> and the script to be tested are in the same folder. When I run <code>pytest</code> on it, I get &quot;collected 0 items&quot;.</p>
  <p>I am new to <code>pytest</code>, and but I am unable to run their examples successfully. What am I missing here?</p>
  <p>I am running Python version 3.5.1 and pytest version 2.8.1 on Windows 7.</p>
  <p>My <em>test.py</em> code:</p>
  <pre><code>from sort_algos import Sorts
  
  def integer_sort_test():
      myobject1 = Sorts([-100, 10, -10])
      assert myobject1.merge_sort() == [-101, -100, 10]
  </code></pre>
  <p>sort_algos.py is a module containing class <code>Sorts</code>. <em>merge_sort</em> is a method under <code>Sorts</code>.</p>