import ctypes as c
class Point( c.BigEndianStructure ):
	_fields_= [
		( 'x', c.c_int ),
		( 'y', c.c_int )
	]

class Shape( c.BigEndianStructure ):
	_fields_= [
		( 'z', c.c_int ),
		( 'ap', Point )
	]

'''
Traceback (most recent call last):
  File "C:\Documents and Settings\usr\Desktop\working\ng36.py", line 8, in <module>
    class Shape( c.BigEndianStructure ):
  File "c:\programs\python25\lib\ctypes\_endian.py", line 30, in __setattr__
    fields.append((name, _other_endian(typ)) + rest)
  File "c:\programs\python25\lib\ctypes\_endian.py", line 20, in _other_endian
    raise TypeError("This type does not support other endian: %s" % typ)
TypeError: This type does not support other endian: <class '__main__.Point'>
'''