Method Field

python/pyarrow/src/arrow/python/python_to_arrow.cc:135–163

  using field_c_type = typename Traits::c_type;

  static Status Field(PyObject* obj, field_c_type* out, bool* found_attrs) {
    *out = 0;
    for (const MonthDayNanoAttrData* attr = &Traits::attrs[0]; attr->multiplier != 0;
         ++attr) {
      if (attr->multiplier != 1 &&
          ::arrow::internal::MultiplyWithOverflow(
              static_cast<field_c_type>(attr->multiplier), *out, out)) {
        return Status::Invalid("Overflow on: ", (attr - 1)->name,
                               " for: ", internal::PyObject_StdStringRepr(obj));
      }

      OwnedRef field_value(PyObject_GetAttrString(obj, attr->name));
      if (field_value.obj() == nullptr) {
        // No attribute present, skip  to the next one.
        PyErr_Clear();
        continue;
      }
      RETURN_IF_PYERROR();
      *found_attrs = true;
      field_c_type value;
      RETURN_NOT_OK(internal::CIntFromPython(field_value.obj(), &value, attr->name));
      if (::arrow::internal::AddWithOverflow(*out, value, out)) {
        return Status::Invalid("Overflow on: ", attr->name,
                               " for: ", internal::PyObject_StdStringRepr(obj));
      }
    }

    return Status::OK();
  }
};

// Utility for converting single python objects to their intermediate C representations