fix: correct gpu argument format onmt-py

src/rxn/onmt_utils/train_command.py

@@ -3,6 +3,7 @@
 from pathlib import Path
 from typing import Any, Dict, List, Optional, Tuple
 
+import torch
 import yaml
 from rxn.utilities.files import PathLike
 
@@ -212,6 +213,10 @@ def save_to_config_cmd(self, config_file_path: PathLike) -> None:
         # See structure https://opennmt.net/OpenNMT-py/quickstart.html (Step 2: Train)
         train_config: Dict[str, Any] = {}
 
+        # GPUs
+        if torch.cuda.is_available() and self._no_gpu is False:
+            train_config["gpu_ranks"] = [0]
+
         # Dump all cli arguments to dict
         for kwarg, value in self._kwargs.items():
             if self.is_valid_kwarg_value(kwarg, value):