task(cat): convert JS code to python

Author: jakr-s

implement-shell-tools/cat/cat.py

@@ -0,0 +1,50 @@
+import argparse
+import sys
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(
+        description="Reads file(s) and writes them to the standard output",
+    )
+    parser.add_argument("paths", nargs="+", help="The file path(s) to process")
+    parser.add_argument(
+        "-n",
+        action="store_true",
+        dest="number_all",
+        help="Number the output lines, starting at 1.",
+    )
+    parser.add_argument(
+        "-b",
+        action="store_true",
+        dest="number_nonblank",
+        help="Number only non-blank output lines, starting at 1.",
+    )
+    return parser.parse_args()
+
+
+def main():
+    args = parse_args()
+
+    try:
+        for path in args.paths:
+            line_num = 1
+
+            with open(path, "r", encoding="utf-8") as file:
+                for raw_line in file:
+                    line = raw_line.rstrip("\n")
+                    is_blank = line.strip() == ""
+                    should_number = args.number_all or (
+                        args.number_nonblank and not is_blank)
+
+                    if should_number:
+                        print(f"{line_num}  {line}")
+                        line_num += 1
+                    else:
+                        print(line)
+    except OSError as err:
+        print(err, file=sys.stderr)
+
+    return 0
+
+
+main()