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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def spkgps(targ, et, ref, obs):
 """ Compute the geometric position of a target body relative to an observing body. http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/spkgps_c.html :param targ: Target body. :type targ: int :param et: Target epoch. :type et: float :param ref: Target reference frame. :type ref: str :param obs: Observing body. :type obs: int :return: Position of target, Light time. :rtype: tuple """

    targ = ctypes.c_int(targ)
    et = ctypes.c_double(et)
    ref = stypes.stringToCharP(ref)
    obs = ctypes.c_int(obs)
    position = stypes.emptyDoubleVector(3)
    lt = ctypes.c_double()
    libspice.spkgps_c(targ, et, ref, obs, position, ctypes.byref(lt))
    return stypes.cVectorToPython(position), lt.value