Allow setting auto_config in the YAML configuration file (#883)

Author: guillaumekln

docs/configuration.md

@@ -62,6 +62,10 @@ Below is an exhaustive and documented configuration. **You should NOT copy and u
 # The directory is created if it does not exist.
 model_dir: toy-ende
 
+# (optional) Enable automatic parameters based on the selected model.
+# Can also be set with the command line option --auto_config.
+auto_config: true
+
 data:
   # (required for train run type).
   train_features_file: data/toy-ende/src-train.txt

opennmt/bin/main.py

@@ -49,7 +49,7 @@ def main():
     )
     parser.add_argument(
         "--auto_config",
-        default=False,
+        default=None,
         action="store_true",
         help="Enable automatic configuration values.",
     )

opennmt/runner.py

@@ -52,7 +52,7 @@ class Runner(object):
     """Class for running and exporting models."""
 
     def __init__(
-        self, model, config, auto_config=False, mixed_precision=False, seed=None
+        self, model, config, auto_config=None, mixed_precision=False, seed=None
     ):
         """Initializes the runner parameters.
 
@@ -61,7 +61,7 @@ def __init__(
             returns such instance.
           config: The run configuration.
           auto_config: If ``True``, use automatic configuration values defined by
-            :obj:`model`.
+            :obj:`model`. If not set, the parameter is read from the run configuration.
           mixed_precision: Enable mixed precision.
           seed: The random seed to set.
 
@@ -86,6 +86,8 @@ def __init__(
         self._config["data"] = config_util.try_prefix_paths(
             self._config["model_dir"], config["data"]
         )
+        if auto_config is None:
+            auto_config = self._config.get("auto_config", False)
         self._auto_config = auto_config
         self._mixed_precision = mixed_precision
         if seed is not None: