title: optparse: No option string
body: <p>I am trying to use optparse but I am having a problem.</p>
  
  <p>My script usage would be: <code>script &lt;filename&gt;</code></p>
  
  <p>I don't intend to add any option string, such as: <code>script -f &lt;filename&gt;</code> or <code>script --file &lt;filename&gt;</code></p>
  
  <p>Is there any way I can choose not to pass an argument string? Or is there any way I can allow the user to do this:</p>
  
  <pre><code>script -f &lt;filename&gt; 
  script --filename &lt;filename&gt;
  script &lt;filename&gt;
  </code></pre>
  
  <p>All of the above with the same consequence? </p>
  
  <p>I know that I can easily do with this with using <code>argv[1]</code> but the thing is that I might need to add command line support later in the project and add that time I would not want to add <code>optparse</code> support all over. That is the reason I want to use <code>optparse</code>. </p>