def get_filepaths(a_path, ext='txt'):
    """
    Make list of txt files in a_path and remove non txt files
    """
    import os
    files = []
    if os.path.isfile(a_path):
        return [a_path]
    for root, dirs, fs in os.walk(a_path):
        for f in fs:
            if ext:
                if not f.endswith('.' + ext):
                    continue
            if ('Unidentified' not in f and 'unknown' not in f and not f.
                startswith('.')):
                files.append(os.path.join(root, f))
    return files
