title: 0 being passed as an optional parameter to a class' method, param not found
body: <p>I have a class file LinkedListADT.py and within that I have the class LinkedList. One method I have defined for this class is as follows:</p>
  
  <pre><code>def test(self, index=None):
      if index:
          print(str(index))
      else:
          print("Index not found")
  </code></pre>
  
  <p>Now, from my other file (not the class) I have defined the following function:</p>
  
  <pre><code>def test():
      tester = LinkedListADT.LinkedList()
      tester.test(0)
  </code></pre>
  
  <p>The result being printed is "Index not found" -- My question is, can 0 be passed as an optional input to a method or regular function?</p>
  
  <p>I am quite new to Python and I'm assuming 0 is being interpreted as false. Whether or not this is the case, is there a workaround I can use?</p>