title: Using openpyxl to edit a spreadsheet. Cannot write to cells, "cell is read-only error"
body: <p>I'm trying to modify an excel worksheet in Python with Openpyxl, but I keep getting an error that says the cells are read only. I know for a fact that they are not because I've been editing these spreadsheets manually for the past two months and have had no issues. Does anyone have an idea of what might be happening? I'm just trying to get my bearings on editing sheets with openpyxl so it is basic code. </p>
  
  <pre><code>rpt = file
  workbook = openpyxl.load_workbook(filename = os.path.join('./Desktop/',rpt), use_iterators = True) # Tells which wb to open
  wb=workbook
  #worksheets = wb.get_sheet_names() 
  ws = wb.active
  ws['A1'] = 42
  </code></pre>
  
  <p>Any help will be greatly appreciated. Thanks!   </p>
  
  <p>Thanks for the responses, to clarify, I'm not getting a workbook is read only error, it is specifically referring to the cells. I'm not sure what's causing this since I know that the workbook is not a read only workbook. Should I be using a different excel library for python? Is there a more robust excel library?</p>
  
  <p>Thanks!</p>