text: import xlwings as xw
  
  
  def main():
      wb = xw.Book.caller()
      sheet = wb.sheets[0]
      if sheet["A1"].value == "Hello xlwings!":
          sheet["A1"].value = "Bye xlwings!"
      else:
          sheet["A1"].value = "Hello xlwings!"
  
  
  @xw.func
  def hello(name):
      return f"Hello {name}!"
  
  
  if __name__ == "__main__":
      xw.Book("permission.xlsm").set_mock_caller()
      main()
  