title: Argparse: set default text file
body: <p>I am looking to set a text file <code>rand.letter.txt</code> as the default word file in this argparse segment, to be used and read in the program. I would assume this should be situated in row 4-5 down below. How should I do this?</p>
  <p>As you will see I have already done that with the matrix size. But I am struggling when in regards of a file with str characteristics.</p>
  <pre><code>def main():
      print(&quot;WELCOME TO THE MEMORY PUZZLE!&quot;)
  
      parser = argparse.ArgumentParser(description=&quot;Memory game&quot;) 
      parser.add_argument(&quot;words_file&quot;, metavar=&quot;FILE&quot;, nargs=1,
                          help=&quot;Words file&quot;)
  
      parser.add_argument(
          &quot;--matrix-size&quot;,
          metavar=&quot;SIZE&quot;,
          dest=&quot;matrix_size&quot;,
          help=&quot;Matrix size&quot;,
          default=6,
          type=int,
          )
  
      args = parser.parse_args()
  
      game = Game(args.words_file[0], args.matrix_size)
      game.play()
  </code></pre>
  <p>Thank you so much for any help or input!</p>