import re


def clean(s):
    """
    Cleans given string from non-relevant information: links, punctuation, etc.
    :param s: raw string
    :return: cleaned string
    """
    s = re.sub(r"https\S+", " ", s)
    s = re.sub(r"^\s+|\n|\r|\t|\s+$", " ", s)
    s = re.sub(r"[^\w\s\d]", " ", s)
    s = re.sub(r"\s{2,}", " ", s)
    return s.lower().strip()