How to implement a union (C data type) in Python?

[Thomas Heller]

lamote1 at netscape.net (chads) writes:

> How would one implement a union (C data type) in Python, given this
> simple example?
>
> union {
>    struct {
>       int size;
>       float time;
>    } var1;
>    struct {
>       char initial;
>       float time;
>    } var2;
> };

With ctypes ;-)

from ctypes import *

class MyUnion(Union):

    class struct_1(Structure):
        _fields_ = [("size", c_int),
                    ("time", c_float)]

    class struct_2(Structure):
        _fields_ = [("initial", c_char),
                    ("time", c_float)]

    _fields_ = [("var1", struct_1),
                ("var2", struct_2)]

print sizeof(MyUnion)

On Windows, this prints 8.

Thomas