title: Convert xlsx to parquet
body: <p>Is it possible to convert a xlsx excel file in parquet without converting in csv ? 
  The thing is that i have many excel files with each many sheets and i don't want to convert each sheet in csv and then in parquet so i wonder if there is a way to convert directly excel to parquet ? Or maybe, is there a way to do it with nifi ? 
  I wanted to do it this way using a python script </p>
  
  <pre><code>def csv_from_excel():
  
  wb = xlrd.open_workbook('your_workbook.xls')
  sh = wb.sheet_names()
  for i in sh:
      sh = wb.sheet_by_name(i)
      your_csv_file = open('your_csv_file.csv', 'wb')
      wr = csv.writer(your_csv_file, quoting=csv.QUOTE_ALL)
  
      for rownum in xrange(sh.nrows):
          wr.writerow(sh.row_values(rownum))
  
      your_csv_file.close()
  `
  </code></pre>