Re: [ctypes-users] Help with struct arrays

[Nicholas E. <nch...@gm...>]

Thanks Thomas, that makes sense. However using either of the two methods
returns nothing. As far as I can tell, the values are stored in the struct,
the function returns the struct to the python wrapper, but when I attempt
to 'print phin[0].times[0]', instead of the location like last time, I just
get nothing...

I'm super confused. Any guidance would be appreciated!

Nicholas Earl
Graduate Research Assistant
San Diego State University


On Thu, Sep 26, 2013 at 11:12 PM, Thomas Heller <th...@ct...> wrote:

> 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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