cjk-filename-renaming

name	cjk-filename-renaming
description	Guide for renaming files and directories containing Chinese/CJK characters from vendor deliverables. Use this when dealing with non-ASCII filenames from Chinese hardware manufacturers (e.g., GBK-encoded filenames on Linux/UTF-8 systems).

Renaming Files with Non-ASCII (CJK) Characters

Problem

Chinese manufacturers deliver files with CJK characters in filenames that can cause issues on Linux systems (UTF-8). Often the filenames use GBK encoding instead of UTF-8.

Detection and Decoding

1. First, try to decode the byte string as UTF-8.
2. On UnicodeDecodeError, try GBK.
3. Use os.fsencode() / byte paths to avoid encoding issues with os.walk.

def decode_filename(raw_bytes):
    try:
        return raw_bytes.decode('utf-8')
    except UnicodeDecodeError:
        return raw_bytes.decode('gbk', errors='replace')

CJK Unicode Ranges

Relevant Unicode blocks for detection:

• \u4e00-\u9fff – CJK Unified Ideographs (most common)
• \u3400-\u4dbf – CJK Unified Ideographs Extension A
• \uf900-\ufaff – CJK Compatibility Ideographs

Regex pattern:

import re
CJK_PATTERN = re.compile(r'[\u4e00-\u9fff\u3400-\u4dbf\uf900-\ufaff]+')

Replacement Rules

When replacing CJK characters with a placeholder (e.g., xxx):

• Insert separators when adjacent characters are alphanumeric to prevent merging.
• Example: Linux软件 → Linux-xxx (not Linuxxxx)
• Example: 修改说明.txt → xxx.txt

def replace_cjk(name, replacement='xxx'):
    result = CJK_PATTERN.sub(replacement, name)
    # Insert separators where needed
    result = re.sub(r'([a-zA-Z0-9])xxx', r'\1-xxx', result)
    result = re.sub(r'xxx([a-zA-Z0-9])', r'xxx-\1', result)
    return result

Renaming Order

• Rename directories bottom-up (deepest level first) so that parent paths remain valid during renaming.
• On conflicts (target name already exists): Use numbered suffixes (xxx, xxx-2, xxx-3).

Complete Algorithm

import os, re

def rename_cjk_tree(root_path):
    root_bytes = os.fsencode(root_path)
    renames = []

    for dirpath, dirnames, filenames in os.walk(root_bytes, topdown=False):
        # First rename files
        for fname in filenames:
            decoded = decode_filename(fname)
            if CJK_PATTERN.search(decoded):
                new_name = replace_cjk(decoded)
                renames.append((
                    os.path.join(dirpath, fname),
                    os.path.join(dirpath, os.fsencode(new_name))
                ))
        # Then rename directories
        for dname in dirnames:
            decoded = decode_filename(dname)
            if CJK_PATTERN.search(decoded):
                new_name = replace_cjk(decoded)
                renames.append((
                    os.path.join(dirpath, dname),
                    os.path.join(dirpath, os.fsencode(new_name))
                ))

    for old, new in renames:
        os.rename(old, new)