PyArray_CompareFunc of dtype datetime64 returns incorrect value for 'NaT' objects. #19574
Description
Sort order for NaT values got changed in numpy 1.18.0.
PyArray_CompareFunc of dtype datetime64 returns incorrect as per the updated sort order.
This is present with numpy 1.20.2 and 1.21 too.
This is reproducible via the following extension module.
compare_bug.c
#include <Python.h>
#include "numpy/arrayobject.h"
#include "numpy/ndarrayobject.h"
#include "numpy/ndarraytypes.h"
#include "numpy/arrayscalars.h"
#include "numpy/ufuncobject.h"
static PyObject*
reproduce_bug(PyObject* self, PyObject* args) {
PyObject *arr = NULL;
if (!PyArg_ParseTuple(args, "|O", &arr)) {
return Py_None;
}
PyArrayObject *numpy_arr = (PyArrayObject*) arr;
// We just compare 0th and 1st element and print out
// the returned value.
int x = numpy_arr->descr->f->compare(
PyArray_GETPTR1(numpy_arr, 0),
PyArray_GETPTR1(numpy_arr, 1),
numpy_arr
);
printf("DEBUG %d\n", x);
return Py_None;
}
static PyMethodDef bug_functions[] = {
{"bug", (PyCFunction)reproduce_bug, METH_VARARGS, NULL},
{ NULL, NULL, 0, NULL }
};
static struct PyModuleDef numpybugmodule = {
PyModuleDef_HEAD_INIT,
"numpy_bug",
NULL,
-1,
bug_functions
};
PyMODINIT_FUNC
PyInit_numpy_bug(void)
{
return PyModule_Create(&numpybugmodule);
}setup.py
from distutils.core import setup, Extension, DEBUG
import numpy
extra_compile_args = ["-DNDEBUG", "-O3"]
sfc_module = Extension('numpy_bug', sources = ['compare_bug..c'],
include_dirs=[numpy.get_include()],
extra_compile_args=extra_compile_args)
setup(name = 'mtnumpy', version = '1.0',
description = 'Python Package with superfastcode C++ extension',
ext_modules = [sfc_module]
)Running this after installing above:
In [1]: import numpy, numpy_bug
In [2]: numpy_bug.bug(numpy.array(['NaT', '2020-01-01'], dtype='datetime64[s]')) # should print 1 as per new sort order.
DEBUG -1