Bulk Rename Files in a Folder Script

import sys
import json
import os
import random
import string
from datetime import datetime

with open(sys.argv[1], encoding="utf-8") as f:
    inputs = json.load(f)

target_dir = inputs["target_dir"]
base_name = inputs["base_name"]
keep_original = inputs["keep_original"] == "true"
position = inputs["position"]
suffix_type = inputs["suffix_type"]
trim_space = inputs["trim_space"] == "true"
preview_mode = inputs["preview_mode"] == "true"
recursive = inputs["recursive"] == "true"

# Assumption: the separator between base name and suffix is "_"
# Assumption: zero-padding width is auto-adjusted based on the file count
# Assumption: when keep_original is false, an index is appended to base_name to guarantee uniqueness

if recursive:
    file_paths = []
    for dirpath, _, filenames in os.walk(target_dir):
        for f in filenames:
            file_paths.append(os.path.join(dirpath, f))
else:
    file_paths = [
        os.path.join(target_dir, f)
        for f in os.listdir(target_dir)
        if os.path.isfile(os.path.join(target_dir, f))
    ]

total = len(file_paths)

if total == 0:
    print("No target files found.")
    sys.exit(0)

print(f"Target files: {total}")

if preview_mode:
    print("\n[Preview mode] No files will be renamed\n")

digits = len(str(total))
today_str = datetime.now().strftime("%Y%m%d")

success = 0
skip = 0

for i, filepath in enumerate(sorted(file_paths)):
    try:
        dirpath = os.path.dirname(filepath)
        filename = os.path.basename(filepath)
        stem, ext = os.path.splitext(filename)

        if keep_original:
            base = stem
        else:
            base = f"{base_name}_{str(i + 1).zfill(digits)}"

        if trim_space:
            base = base.replace(" ", "").replace("　", "")

        if suffix_type == "yyyymmdd (date)":
            suffix_text = today_str
        elif suffix_type == "001 (sequence)":
            suffix_text = str(i + 1).zfill(digits)
        else:
            suffix_text = ''.join(random.choices(string.ascii_lowercase + string.digits, k=6))

        if position == "Prefix":
            new_stem = f"{suffix_text}_{base}"
        else:
            new_stem = f"{base}_{suffix_text}"

        new_filename = new_stem + ext
        dst = os.path.join(dirpath, new_filename)

        if preview_mode:
            if os.path.exists(dst) and filepath != dst:
                print(f"[Conflict] {filepath} → {new_filename}")
            else:
                print(f"[Planned] {filepath} → {new_filename}")
            success += 1
            continue

        if os.path.exists(dst) and filepath != dst:
            print(f"[Skipped] A file with the same name already exists: {filepath}", file=sys.stderr)
            skip += 1
            continue

        os.rename(filepath, dst)
        print(f"[{i+1}/{total}] {filepath} → {new_filename}")
        success += 1

    except Exception as e:
        print(f"[Error] {filepath}: {e}", file=sys.stderr)
        skip += 1

if preview_mode:
    print(f"\nPreview complete: {success} planned rename(s) listed")
    print("Uncheck \"Preview mode\" and run again to actually rename the files")
else:
    print(f"\nDone: {success} renamed / {skip} skipped")