How can I use the ctypes "cast" function to cast one integer format to another, to obtain the same effect as in C:
int var1 = 1;
unsigned int var2 = (unsigned int)var1;
?
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4 Answers
>>> cast((c_int*1)(1), POINTER(c_uint)).contents
c_uint(1L)
>>> cast((c_int*1)(-1), POINTER(c_uint)).contents
c_uint(4294967295L)
Comments
Simpler than using cast() is using .value on the variable:
>>> from ctypes import *
>>> x=c_int(-1)
>>> y=c_uint(x.value)
>>> print x,y
c_long(-1) c_ulong(4294967295L)
Comments
Integer to Structure typecasting
from ctypes import *
class head(Structure):
_fields_=[
('x',c_ubyte),
('y',c_ubyte)
]
x = c_uint(0x3234)
px= cast(pointer(x),POINTER(head))
print(px[0].x)
print(px[0].y)
Comments
You may want to have a look at http://docs.python.org/2/library/ctypes.html#type-conversions
An example is ctypes.cast((ctype.c_byte*4)(), ctypes.POINTER(ctypes.c_int))
1 Comment
MattyZ
Thanks for the reply. I have read the documentation, but I am still unclear as to how to perform the conversion mentioned in my post.