Re: Help with struct arrays

Am 27.09.2013 06:37, schrieb Nicholas Earl:
> Hello all! I'm having difficulties accessing the information in a
> returned struct object. I'm quite new to C/C++, but I've had plenty of
> experience with C#, so I think I have my foot in the door.
>
> I have a struct defined as
>
> class PhotoInfo(ctypes.Structure):
>      _fields_ = [
>          ('times', ctypes.POINTER(ctypes.c_double)),
>          ('fluxes', ctypes.POINTER(ctypes.c_double)),
>      ]
>
> with the restype defined like
>
> def main():
>      lib = ctypes.cdll.LoadLibrary('photoroutine.so')
>
>      start = lib.start
>      PhotoInfoPtr = ctypes.POINTER(PhotoInfo)
>      start.restype = PhotoInfoPtr
>
> But when I call
>
> phin = start()
>
> I can't get to the time and flux info the returned object has. I've
> tried using
>
> phin.contents.times
>
> but it just gives me a location; i.e. <__main__.LP_c_double object at
> 0x159fef0>
>
> How do I get the actual array of times and fluxes?

Try 'phin[0].times[0]' or 'phin.contents.times.contents'.
The former is the preferred idiom.

Thomas



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