def METHOD_NAME(length=20):
    res = []
    alphabet = [
        'a',
        'b',
        'c',
        'd',
        'e',
        'f',
        'g',
        'h',
        'i',
        'j',
        'k',
        'l',
        'm',
        'n',
        'o',
        'p',
        'q',
        'r',
        's',
        't',
        'u',
        'v',
        'w',
        'x',
        'y',
        'z',
        ' ',
    ]
    for _ in range(1, length):
        s_length = np.random.randint(1, length)
        res.append(''.join(np.random.choice(alphabet, s_length)))
    return res