ctypes: how to make a structure pointer to point to a buffer

[Guest]

first, I'm try the POINTER to convesion the pointer type. but failed.

class STUDENT(Structure):
_fields_ = [('name', c_int),
('id', c_int),
('addition', c_ubyte)]

buffer = c_byte * 1024
student_p = cast(buffer, POINTER(STUDENT))

The parameter of the POINTER must be ctypes type.
How could I attach the buffer pointer to the structure STUDENT ?

 

[Diez B. Roggisch]

first, I'm try the POINTER to convesion the pointer type. but failed.

class STUDENT(Structure):
_fields_ = [('name', c_int),
('id', c_int),
('addition', c_ubyte)]

buffer = c_byte * 1024
student_p = cast(buffer, POINTER(STUDENT))

The parameter of the POINTER must be ctypes type.
How could I attach the buffer pointer to the structure STUDENT ?

I think it should work like this:

from ctypes import *

class STUDENT(Structure):
_fields_ = [('name', c_int),
('id', c_int),
('addition', c_ubyte)]

buffer = (c_byte * 1024)()
buffer_p = pointer(buffer)
student_p = cast(buffer_p, POINTER(STUDENT))

print student_p


Diez