title: Error when invoking lambda function as a ZIP file
body: <p>This is the error I get when I try to invoke my lambda function as a ZIP file. </p>
  
  <blockquote>
    <p>"The file lambda_function.py could not be found. Make sure your
    handler upholds the format: file-name.method."</p>
  </blockquote>
  
  <p>What am I doing wrong?</p>