secure_filename with chinese

secure_filename.py

_filename_gbk_strip_re = re.compile(u"^[\u4e00-\u9fa5A-Za-z0-9_.-]+$")


def secure_filename(filename):
    if isinstance(filename, text_type):
        from unicodedata import normalize
        filename = normalize('NFKD', filename).encode('utf-8', 'ignore')
        if not PY2:
            filename = filename.decode('utf-8')
    for sep in os.path.sep, os.path.altsep:
        if sep:
            filename = filename.replace(sep, ' ')

    a = '_'.join(filename.split())
    b = _filename_gbk_strip_re.sub('', a)
    filename = str(b).strip('._')

    if os.name == 'nt' and filename and \
                    filename.split('.')[0].upper() in _windows_device_files:
        filename = '_' + filename

    return filename