title: Why is an instance value resetting after each update
body: <pre><code>class test:
      def __init__(self):
          self.check = [False,False,False,False,False,False,False,False]
  
      def test(self,x):
          self.check[x]=True
          print(self.check)
  
  test().test(5)
  test().test(4)
  test().test(3)
  test().test(1)
  print(&quot;|----------------------------------------------------------------------|&quot;)
  print(test().check)
  
  </code></pre>
  <p>Why it doesn't print out:</p>
  <pre><code>[False,True,False,True,True,True,False,False] 
  </code></pre>
  <p>And it instead prints the initial:</p>
  <p>[False,False,False,False,False,False,False,False]</p>