import string


def remove_punctuation_and_lower(s):
    """
    This will return a string without puntuation and all words are in lower-case.
    The punctuation symbols are get from the module 'string'.
    The set of punctuation symbols are '!"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}~'
    """
    return s.translate(str.maketrans('', '', string.punctuation)).lower()