Function MayHaveNaN

python/pyarrow/src/arrow/python/helpers.cc:283–290

template Status CIntFromPython(PyObject*, uint64_t*, const std::string&);

inline bool MayHaveNaN(PyObject* obj) {
  // Some core types can be very quickly type-checked and do not allow NaN values
  const int64_t non_nan_tpflags = Py_TPFLAGS_LONG_SUBCLASS | Py_TPFLAGS_LIST_SUBCLASS |
                                  Py_TPFLAGS_TUPLE_SUBCLASS | Py_TPFLAGS_BYTES_SUBCLASS |
                                  Py_TPFLAGS_UNICODE_SUBCLASS | Py_TPFLAGS_DICT_SUBCLASS |
                                  Py_TPFLAGS_BASE_EXC_SUBCLASS | Py_TPFLAGS_TYPE_SUBCLASS;
  return !PyType_HasFeature(Py_TYPE(obj), non_nan_tpflags);
}

bool PyFloat_IsNaN(PyObject* obj) {
  return PyFloat_Check(obj) && std::isnan(PyFloat_AsDouble(obj));