def select_extensions(file_list, acceptable_extensions):
    """
    Returns list of files with specified file extensions.
    
    Arguments:
        file_list:             list of files to filter
        acceptable_extensions: list of extensions user wishes to keep
    Returns:
        List of files with specified extensions
    Raises:
        None
    """
    return [file for file in file_list if ('.').join(file.split('.')[-1:]) in acceptable_extensions]