Enum for confidence level

Closes #185 (closed)

dan/ocr/predict/__init__.py

@@ -5,6 +5,7 @@ Predict on an image using a trained DAN model.
 
 import pathlib
 
+from dan.ocr.predict.attention import Level
 from dan.ocr.predict.prediction import run
 from dan.utils import parse_tokens
 
@@ -81,7 +82,7 @@ def add_predict_parser(subcommands) -> None:
     parser.add_argument(
         "--confidence-score-levels",
         default=[],
-        type=str,
+        type=Level,
         nargs="+",
         help="Levels of confidence scores. Should be a list of any combinaison of ['char', 'word', 'line'].",
         required=False,
@@ -94,10 +95,9 @@ def add_predict_parser(subcommands) -> None:
     )
     parser.add_argument(
         "--attention-map-level",
-        type=str,
-        choices=["line", "word", "char"],
-        default="line",
-        help="Level of attention maps.",
+        type=Level,
+        default=Level.Line,
+        help="Level to plot the attention maps. Should be in ['line', 'word', 'char'].",
         required=False,
     )
     parser.add_argument(