Traceback (most recent call last):
  File "bin/py", line 33, in <module>
    execfile(__file__)
  File "overwriting.py", line 11, in <module>
    sheet2.write(0,0,'new')
  File "Worksheet.py", line 1032, in write
    self.row(r).write(c, label, style)
  File "Row.py", line 233, in write
    StrCell(self.__idx, col, style_index, self.__parent_wb.add_str(label))
  File "Row.py", line 152, in insert_cell
    raise Exception(msg)
Exception: Attempt to overwrite cell: sheetname=u'Sheet 2' rowx=0 colx=0