Add type hints to the main module

src/main.py

@@ -1,10 +1,10 @@
-from argparse import ArgumentParser
+from argparse import ArgumentParser, Namespace
 from time import time
 
 from model import run
 
 
-def parse_arguments():
+def parse_arguments() -> Namespace:
     parser = ArgumentParser()
     parser.add_argument(
         "data_file", help="FASTQ file containing the sequences with errors"
@@ -15,7 +15,7 @@ def parse_arguments():
     return parser.parse_args()
 
 
-def main():
+def main() -> None:
     args = parse_arguments()
     start_time = time()
     run(data_file=args.data_file, label_file=args.label_file)