import re


def clean_link(link):
    """Normalize source, this is needed since some source has http, or www.
    and others doesn't"""
    if link.startswith('http') or link.startswith('https'):
        link = re.sub(r'http[s]?://', '', link)
    if link.startswith('www.'):
        link = re.sub(r'www\.', '', link)
    return link