Add scripts to convert raw file to text-only json

Raw text file format (line by line):
    """
    <text_1>
    <text_2>
    ...
    <text_n>
    """

scripts/data_preprocess/raw2textonly.py

@@ -0,0 +1,81 @@
+#!/usr/bin/env python
+# coding=utf-8
+# Copyright 2023 Statistics and Machine Learning Research Group at HKUST. All rights reserved.
+"""
+Converts a raw text file, separated by lines, into a "text-only" formatted json.
+"""
+from __future__ import absolute_import
+
+import argparse
+import json
+import textwrap
+import sys
+
+def parse_argument(sys_argv):
+    """Parses arguments from command line.
+    Args:
+        sys_argv: the list of arguments (strings) from command line.
+    Returns:
+        A struct whose member corresponds to the required (optional) variable.
+        For example,
+        ```
+        args = parse_argument(['main.py' '--input', 'a.txt', '--num', '10'])
+        args.input       # 'a.txt'
+        args.num         # 10
+        ```
+    """
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.RawTextHelpFormatter)
+
+    # Training parameters
+    parser.add_argument(
+        "--dataset_path", type=str,
+        default=None,
+        help=textwrap.dedent("input dataset path, reads from stdin by default")
+    )
+    parser.add_argument(
+        "--output_path", type=str,
+        default=None,
+        help=textwrap.dedent("output dataset path, writes to stdout by default")
+    )
+
+    # Parses from commandline
+    args = parser.parse_args(sys_argv[1:])
+
+    return args
+
+
+def raw2textonly(fin):
+    """
+    Converts raw text to text-only format.
+
+    Args:
+        fin: the input file description of the raw text file.
+    Returns:
+        a dict with "text-only" format.
+    """
+    data_dict = {
+        "type": "text_only",
+        "instances": [ { "text": line.strip() } for line in fin ],
+    }
+    return data_dict
+
+
+def main():
+    args = parse_argument(sys.argv)
+
+    if args.dataset_path is not None:
+        with open(args.dataset_path, "r") as fin:
+            data_dict = raw2textonly(fin)
+    else:
+        data_dict = raw2textonly(sys.stdin)
+
+    if args.output_path is not None:
+        with open(args.output_path, "w") as fout:
+            json.dump(data_dict, fout, indent=4, ensure_ascii=False)
+    else:
+        json.dump(data_dict, sys.stdout, indent=4, ensure_ascii=False)
+
+
+if __name__ == "__main__":
+    main()