def secure_filename(filename):
    r"""Borrowed from :mod:`werkzeug.utils`, under the BSD 3-clause license.

    Pass it a filename and it will return a secure version of it.  This
    filename can then safely be stored on a regular file system and passed
    to :func:`os.path.join`.  The filename returned is an ASCII only string
    for maximum portability.

    On windows systems the function also makes sure that the file is not
    named after one of the special device files.

    >>> secure_filename("My cool movie.mov")
    'My_cool_movie.mov'
    >>> secure_filename("../../../etc/passwd")
    'etc_passwd'
    >>> secure_filename(u'i contain cool \xfcml\xe4uts.txt')
    'i_contain_cool_umlauts.txt'

    The function might return an empty filename.  It's your responsibility
    to ensure that the filename is unique and that you generate random
    filename if the function returned an empty one.

    :param filename: the filename to secure
    """
    _filename_ascii_strip_re = re.compile(r'[^A-Za-z0-9_.-]')
    _windows_device_files = ('CON', 'AUX', 'COM1', 'COM2', 'COM3', 'COM4',
                             'LPT1', 'LPT2', 'LPT3', 'PRN', 'NUL')
    if isinstance(filename, text_type):
        from unicodedata import normalize
        filename = normalize('NFKD', filename).encode('ascii', 'ignore')
        if not PY2:
            filename = filename.decode('ascii')
    for sep in os.path.sep, os.path.altsep:
        if sep:
            filename = filename.replace(sep, ' ')
    filename = str(_filename_ascii_strip_re.sub('', '_'.join(
                   filename.split()))).strip('._')

    # on nt a couple of special files are present in each folder.  We
    # have to ensure that the target file is not such a filename.  In
    # this case we prepend an underline
    if os.name == 'nt' and filename and \
       filename.split('.')[0].upper() in _windows_device_files:
        filename = '_' + filename

    return filename
def parsed_error_msg(self):
        """
        Parse the error messages we receive from SoftwareSecure

        Error messages are written in the form:

            `[{"photoIdReasons": ["Not provided"]}]`

        Returns:
            str[]: List of error messages.
        """
        parsed_errors = []
        error_map = {
            'EdX name not provided': 'name_mismatch',
            'Name mismatch': 'name_mismatch',
            'Photo/ID Photo mismatch': 'photos_mismatched',
            'ID name not provided': 'id_image_missing_name',
            'Invalid Id': 'id_invalid',
            'No text': 'id_invalid',
            'Not provided': 'id_image_missing',
            'Photo hidden/No photo': 'id_image_not_clear',
            'Text not clear': 'id_image_not_clear',
            'Face out of view': 'user_image_not_clear',
            'Image not clear': 'user_image_not_clear',
            'Photo not provided': 'user_image_missing',
        }

        try:
            messages = set()
            message_groups = json.loads(self.error_msg)

            for message_group in message_groups:
                messages = messages.union(set(*six.itervalues(message_group)))

            for message in messages:
                parsed_error = error_map.get(message)

                if parsed_error:
                    parsed_errors.append(parsed_error)
                else:
                    log.debug(u'Ignoring photo verification error message: %s', message)
        except Exception:   # pylint: disable=broad-except
            log.exception(u'Failed to parse error message for SoftwareSecurePhotoVerification %d', self.pk)

        return parsed_errors