Allow multiple override flags

docs/src/getting-started/override.rst

@@ -52,13 +52,12 @@ possibility. The changes above can be achieved by typing:
 .. code-block:: bash
 
    mtt train options.yaml \
-      -r architecture.model.soap.cutoff=7.0,architecture.training.num_epochs=200
+      -r architecture.model.soap.cutoff=7.0 -r architecture.training.num_epochs=200
 
 Here, the ``-r`` or equivalent ``--override`` flag is used to parse the override flags.
 The syntax follows a dotlist-style string format where each level of the options is
-seperated by a ``.`` and each separate option to override is separated by a comma.
-As a further example, to use single precision for your training you can add
-``-r base_precision=32``.
+seperated by a ``.``. As a further example, to use single precision for your training
+you can add ``-r base_precision=32``.
 
 .. note::
    Command line overrides allow adding new values to your training parameters and

src/metatrain/cli/train.py

@@ -83,8 +83,9 @@ def _add_train_model_parser(subparser: argparse._SubParsersAction) -> None:
         "-r",
         "--override",
         dest="override_options",
-        type=lambda string: OmegaConf.from_dotlist(string.split(",")),
-        help="Command line override flags.",
+        action="append",
+        help="Command-line override flags.",
+        default=[],
     )
 
 
@@ -93,8 +94,7 @@ def _prepare_train_model_args(args: argparse.Namespace) -> None:
     args.options = OmegaConf.load(args.options)
     # merge/override file options with command line options
     override_options = args.__dict__.pop("override_options")
-    if override_options is None:
-        override_options = {}
+    override_options = OmegaConf.from_dotlist(override_options)
 
     args.options = OmegaConf.merge(args.options, override_options)
 

tests/cli/test_train_model.py

@@ -106,8 +106,8 @@ def test_train(capfd, monkeypatch, tmp_path, output):
 @pytest.mark.parametrize(
     "overrides",
     [
-        "architecture.training.num_epochs=2",
-        "architecture.training.num_epochs=2,architecture.training.batch_size=3",
+        ["architecture.training.num_epochs=2"],
+        ["architecture.training.num_epochs=2", "architecture.training.batch_size=3"],
     ],
 )
 def test_command_line_override(monkeypatch, tmp_path, overrides):
@@ -116,7 +116,9 @@ def test_command_line_override(monkeypatch, tmp_path, overrides):
     shutil.copy(DATASET_PATH_QM9, "qm9_reduced_100.xyz")
     shutil.copy(OPTIONS_PATH, "options.yaml")
 
-    command = ["mtt", "train", "options.yaml", "-r", overrides]
+    command = ["mtt", "train", "options.yaml"]
+    for override in overrides:
+        command += ["-r", override]
 
     subprocess.check_call(command)
 
@@ -126,7 +128,7 @@ def test_command_line_override(monkeypatch, tmp_path, overrides):
     restart_options = OmegaConf.load(restart_glob[0])
     assert restart_options["architecture"]["training"]["num_epochs"] == 2
 
-    if len(overrides.split()) == 2:
+    if len(overrides) == 2:
         assert restart_options["architecture"]["training"]["batch_size"] == 3