Allows changing in-memory partno field of a Partition instance:
>>> import fdisk
>>> pa = fdisk.Partition()
>>> pa.partno = 3
>>> pa
<libfdisk.Partition object at 0x7f4603a38f30, partno=3>
If partno is unset repr shows 'None':
>>> import fdisk
>>> pa = fdisk.Partition()
>>> pa
<libfdisk.Partition object at 0x7f86c4338f30, partno=None>
Undefined values in libfdisk should map to None type in Python.
Py_BuildValue("%d", -1); is also incorrectly formatted and raises an
error when executed.
Jose M. Guisado
Jose M. Guisado Gomez