title: Non-Default parameter follows default parameters
body: <p>I keep getting an error message on my function parameters.</p>
  
  <p>I've seen some other questions that are similar but I struggle to understand the answer and those people also had different situations which were more complex.</p>
  
  <pre><code>def check(user_answer='', list_of_blanks, letters):
      x = 0
      for letter in letters:
          if letter == user_answer:
              list_of_blanks[letters.index(user_answer)] = user_answer
              x += 1
      if x == 0:
          return False
      else:
          str(list_of_blanks)
      list_of_blanks = ''.join(list_of_blanks)
      return list_of_blanks
  </code></pre>
  
  <p>pycharm highlights "list_of_blanks, letters" (function parameters) and gives me the error which says: </p>
  
  <pre><code>Non-Default parameter follows default parameter.
  </code></pre>
  
  <p>If I try to default the parameter to an empty list like so:</p>
  
  <pre><code>list_of_blanks=[], letters=[]
  </code></pre>
  
  <p>then I get this error: </p>
  
  <pre><code>Default argument value is mutable.
  </code></pre>