title: Python How to use ExcelWriter to write into an existing worksheet
body: <p>I am trying to use ExcelWriter to write/add some information into a workbook that contains multiple sheets. 
  First time when I use the function, I am creating the workbook with some data. In the second call, I would like to add some information into the workbook in different locations into all sheets.</p>
  
  <pre><code>def Out_Excel(file_name,C,col): 
      writer = pd.ExcelWriter(file_name,engine='xlsxwriter')
      for tab in tabs:    # tabs here is provided from a different function that I did not write here to keep it simple and clean
          df = DataFrame(C)    # the data is different for different sheets but I keep it simple in this case
          df.to_excel(writer,sheet_name = tab, startcol = 0 + col, startrow = 0)
      writer.save()
  </code></pre>
  
  <p>In the main code I call this function twice with different col to print out my data in different locations. </p>
  
  <pre><code>Out_Excel('test.xlsx',C,0)
  Out_Excel('test.xlsx',D,10)
  </code></pre>
  
  <p>But the problem is that doing so the output is just the second call of the function as if the function overwrites the entire workbook. I guess I need to load the workbook that already exists in this case? 
  Any help? </p>