code: def replace(self, findpos, find_string, replace_string):
          
  
          # Mark content as changed
          post_command_event(self.main_window, self.ContentChangedMsg)
  
          old_code = self.grid.code_array(findpos)
          new_code = old_code.replace(find_string, replace_string)
  
          self.grid.code_array[findpos] = new_code
          self.grid.actions.cursor = findpos
  
          statustext = _("Replaced {old} with {new} in cell {key}.")
          statustext = statustext.format(old=old_code, new=new_code, key=findpos)
  
          post_command_event(self.main_window, self.StatusBarMsg,
                             text=statustext)
  
          self.grid.ForceRefresh()
docs: Replaces occurrences of find_string with replace_string at findpos
  
          and marks content as changed
  
          Parameters
          ----------
  
          findpos: 3-Tuple of Integer
          \tPosition in grid that shall be replaced
          find_string: String
          \tString to be overwritten in the cell
          replace_string: String
          \tString to be used for replacement