title: How to write on existing excel files without losing previous information using python?
body: <p>I need to write a program to scrap daily quote from a certain web page and collect them into a single excel file. I wrote something which finds next empty row and starts writing new quotes on it but deletes previous rows too:</p>
  
  <pre><code>wb = openpyxl.load_workbook('gold_quote.xlsx')
  sheet = wb.get_sheet_by_name('Sheet1')
  .
  .
  .
  z = 1
  x = sheet['A{}'.format(z)].value
  
  while x != None:
      x = sheet['A{}'.format(z)].value
      z += 1
  
  writer = pd.ExcelWriter('quote.xlsx')
  df.to_excel(writer, sheet_name='Sheet1',na_rep='', float_format=None,columns=['Date', 'Time', 'Price'], header=True,index=False, index_label=None, startrow=z-1, startcol=0, engine=None,merge_cells=True, encoding=None, inf_rep='inf', verbose=True, freeze_panes=None)
  writer.save()
  </code></pre>