title: Unit testing in PyCharm
body: <p>Alright, so I am doing Python Crash Course exercies for unit tests chapter and I can't quite get it to work using PyCharm.</p>
  
  <p>My "project" literally consists of two trivial files:</p>
  
  <p>city_functions.py:</p>
  
  <pre><code>def city_country(city, country):
      result = '{0}, {1}'.format(city.title(), country.title())
      return result
  </code></pre>
  
  <p>test_cities.py:</p>
  
  <pre><code>import unittest
  from city_functions import city_country
  
  
  class CityTestCase(unittest.TestCase):
      """Tests for 'city_functions.city_country' function."""
  
      def test_city_country(self):
          result = city_country('london', 'england')
          self.assertEqual(result, 'London, England')
  
  unittest.main()
  </code></pre>
  
  <p>Now, when I am trying to run the module from PyCharm I get:</p>
  
  <pre><code>(...)
  ----------------------------------------------------------------------
  Ran 0 tests in 0.000s
  
  OK
  </code></pre>
  
  <p>but it works, when I run it from command line:</p>
  
  <pre><code>&gt; python -m test_cities
  .
  ----------------------------------------------------------------------
  Ran 1 test in 0.000s
  
  OK
  </code></pre>
  
  <p>Are there any shenanigans with PyCharm configuration to get it to work? I've read some posts about naming conventions (that test function and the whole module MUST start with 'test', but it already does in my case).</p>