title: parametrizing test classes in pytest
body: <p>I have a class for testing some of my code. I would like to parametrize the setup and rerun the class with different parameters:</p>
  
  <pre><code>class TestNormalLTEPlasma:
  
  
      def setup(self, t=10000):
          self.plasma = plasma.LTEPlasma.from_abundance(t, {'Si':1.0}, 1e-13, atom_data, 10*86400)
  
      def test_beta_rad(self):
          assert self.plasma.beta_rad == 1 / (10000 * constants.k_B.cgs.value)
  
      def test_t_electron(self):
          assert self.plasma.t_electron == 0.9 * self.plasma.t_rad
  
      def test_saha_calculation_method(self):
          assert self.plasma.calculate_saha == self.plasma.calculate_saha_lte
  </code></pre>
  
  <p>I would like to run this class going from t=2000 to t=20000 in steps of 1000.</p>