passing pointer? about nimpy

[JorySchossau]

To deter more #denvercoder9 situations, this is for posterity:

   let np = pyImport("numpy")                                                                         
   let ctypes = pyImport("ctypes")                                                                    
   var mem = cast[ptr UncheckedArray[cfloat]](alloc0 4*sizeof(cfloat))                                    
   var thepointer = ctypes.cast(cast[uint](mem),ctypes.POINTER(nimpy.getAttr(ctypes, "c_float")))     
   var numpyarray = np.ctypeslib.as_array(thepointer, (4,))