os.truncate(), os.ftruncate() and truncate() methods of file-like objects raise OverflowError when the argument is out of ranger of certain C type. It would be better to extend the behavior of small integers to large integers. ValueError is raised for negative integers and it should be raised for negative integers out of range. Values larger than the current size should be ignored in BytesIO.truncate() and StringIO.truncate(). BytesIO.truncate() and StringIO.truncate() should never raise OverflowError. Since the behavior of underlying OS functions is OS and FS depended, OverflowError can be raised for large integers in os.truncate(), os.ftruncate() and FileIO.truncate().