Function ImportPresentIntervalTypes

python/pyarrow/src/arrow/python/inference.cc:48–78

Assigns a tuple to interval_types_tuple containing the nametuple for MonthDayNanoIntervalType and if present dateutil's relativedelta and pandas DateOffset.

// MonthDayNanoIntervalType and if present dateutil's relativedelta and
// pandas DateOffset.
Status ImportPresentIntervalTypes(OwnedRefNoGIL* interval_types_tuple) {
  OwnedRef relative_delta_module;
  // These are Optional imports so swallow errors.
  OwnedRef relative_delta_type;
  // Try to import pandas to get types.
  internal::InitPandasStaticData();
  if (internal::ImportModule("dateutil.relativedelta", &relative_delta_module).ok()) {
    RETURN_NOT_OK(internal::ImportFromModule(relative_delta_module.obj(), "relativedelta",
                                             &relative_delta_type));
  }

  PyObject* date_offset_type = internal::BorrowPandasDataOffsetType();
  interval_types_tuple->reset(
      PyTuple_New(1 + (date_offset_type != nullptr ? 1 : 0) +
                  (relative_delta_type.obj() != nullptr ? 1 : 0)));
  RETURN_IF_PYERROR();
  int index = 0;
  PyTuple_SetItem(interval_types_tuple->obj(), index++,
                  internal::NewMonthDayNanoTupleType());
  RETURN_IF_PYERROR();
  if (date_offset_type != nullptr) {
    Py_XINCREF(date_offset_type);
    PyTuple_SetItem(interval_types_tuple->obj(), index++, date_offset_type);
    RETURN_IF_PYERROR();
  }
  if (relative_delta_type.obj() != nullptr) {
    PyTuple_SetItem(interval_types_tuple->obj(), index++, relative_delta_type.detach());
    RETURN_IF_PYERROR();
  }
  return Status::OK();
}

}  // namespace