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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def not_user_filter(config, message, fasnick=None, *args, **kw):
 """ Everything except a particular user Use this rule to exclude messages that are associated with one or more users. Specify several users by separating them with a comma ','. """


    fasnick = kw.get('fasnick', fasnick)
    if not fasnick:
        return False

    fasnick = (fasnick or []) and fasnick.split(',')
    valid = True
    for nick in fasnick:
        if nick.strip() in fmn.rules.utils.msg2usernames(message, **config):
            valid = False
            break

    return valid