title: How to reset\reload env variable when using pytest parametrize?
body: <p>I got the following project</p>
  <pre><code>project
  │   README.md
  │  
  │
  └───workers
  │   └───func
  │       │   func.py
  
  │   
  └───tests
  │   └───__init__,py
  │   └───func
  │       │   test_foo.py
  
  </code></pre>
  <p>func.py :</p>
  <pre><code>import os
  
  
  AUTH_DOMAIN = os.getenv(&quot;AUTH_DOMAIN&quot;)
  assert AUTH_DOMAIN
  
  def foo():
    return AUTH_DOMAIN
  </code></pre>
  <p>test_func.py:</p>
  <pre><code>import os
  
  import pytest
  
  
  @pytest.mark.parametrize(&quot;domain, location&quot;, [
      (&quot;a.com&quot;, &quot;a.com&quot;),
      (&quot;b.com&quot;, &quot;b.com&quot;)
  ])
  def test_me(domain, location):
      os.environ['AUTH_DOMAIN'] = domain
      from workers.func.func import foo
      res = foo()
      assert res == location
      del os.environ['AUTH_DOMAIN']
  </code></pre>
  <p>at the moment the second test fail because <strong>AUTH_DOMAIN</strong> is still with the value from the first test</p>
  <pre><code># result in second run
  assert 'a.com' == 'b.com'
  </code></pre>
  <p>how can I reimport and update the env param?</p>