title: python wkhtmltopdf to Generate pdf
body: <p>I am able to generate the pdf using the Command Line wkhtmltopdf but when i use it in python lib </p>
  
  <pre><code>from wkhtmltopdf import WKhtmlToPdf
  
  wkhtmltopdf = WKhtmlToPdf(
      url='http://www.wikipedia.org',
      output_file='a.pdf',
  )
  </code></pre>
  
  <p>i get</p>
  
  <pre><code>'Exception: Missing url and output file arguments'
  </code></pre>