add subpackage with cli

src/read_sequencing/__init__.py

+"""Placeholder package."""
+
+__version__ = '0.1.0'

src/read_sequencing/cli.py

+import argparse
+from read_sequencing import read_sequencing
+
+
+def parse_args() -> argparse.Namespace:
+    """Parse CLI arguments.
+
+    Returns:
+        Parsed CLI arguments.
+    """
+
+    # initiate parser
+    parser = argparse.ArgumentParser(description='Simulate the Sequencing of Reads')
+
+    # add arguments
+    parser.add_argument('--frag_file_name',
+                        type=str,
+                        help='input file name')
+
+    parser.add_argument('--output_file_name',
+                        type=str,
+                        help='output file name')
+
+    parser.add_argument('--num_reads',
+                        type=int,
+                        help='desired number of reads')
+
+    parser.add_argument('--read_len',
+                        type=int,
+                        help='length of each read')
+
+    return parser.parse_args()
+
+
+def main() -> None:
+    """Main function.
+
+    Interprets the arguments from the commandline,
+    Runs the functions read_sequencing.
+    """
+
+    args = parse_args()
+    read_sequencing(frag_file_name=args.frag_file_name,
+                    output_file_name=args.output_file_name,
+                    num_reads=args.num_reads,
+                    read_len=args.read_len)
+
+
+if __name__ == '__main__':
+    """Initiates main.
+    Calls main function only if run from commandline, but not if imported.
+    """
+    main()