Python: safely write to a file

file_helper.py

def safe_write_file(file_path, data, tmp_path_generator_callback=None):
    """
    :type file_path: str
    :param data: what write
    :type tmp_path_generator_callback: function
    """
    if os.path.isdir(file_path) or os.path.islink(file_path):
        raise Exception('File %s must not be a link or directory' % file_path)

    if tmp_path_generator_callback is None:
        tmp_path_generator_callback = get_file_path_tmp_file

    # get path to temporary file
    file_path_tmp = tmp_path_generator_callback(file_path)
    try:
        # write to temporary file
        with open(file_path_tmp, 'w+b') as file_path_tmp_obj:
            file_path_tmp_obj.write(data)

        # copy permissions for temporary file (included chattr)
        if os.path.isfile(file_path):
            shutil.copystat(file_path, file_path_tmp)

        # moved file
        os.rename(file_path_tmp, file_path)
    finally:
        # if something wrong, delete temporary file
        try:
            os.remove(file_path_tmp)
        except:
            pass

def get_file_path_tmp_file(file_path):
    """ Returns a recommended path for a temporary file
    :type file_path: str
    :rtype: str
    """
    result_file_path = file_path + '_tmp'
    while os.path.exists(result_file_path):
        result_file_path + str(random.randint(0, 9))

    return result_file_path