@utils.cached_slot_property('_clean_content')
    def clean_content(self):

        transformations = {
            re.escape('<#{0.id}>'.format(channel)): '#' + channel.name
            for channel in self.channel_mentions
        }

        mention_transforms = {
            re.escape('<@{0.id}>'.format(member)): '@' + member.display_name
            for member in self.mentions
        }

        # add the <@!user_id> cases as well..
        second_mention_transforms = {
            re.escape('<@!{0.id}>'.format(member)): '@' + member.display_name
            for member in self.mentions
        }

        transformations.update(mention_transforms)
        transformations.update(second_mention_transforms)

        if self.server is not None:
            role_transforms = {
                re.escape('<@&{0.id}>'.format(role)): '@' + role.name
                for role in self.role_mentions
            }
            transformations.update(role_transforms)

        def repl(obj):
            return transformations.get(re.escape(obj.group(0)), '')

        pattern = re.compile('|'.join(transformations.keys()))
        result = pattern.sub(repl, self.content)

        transformations = {
            '@everyone': '@\u200beveryone',
            '@here': '@\u200bhere'
        }

        def repl2(obj):
            return transformations.get(obj.group(0), '')

        pattern = re.compile('|'.join(transformations.keys()))
        return pattern.sub(repl2, result)
A property that returns the content in a "cleaned up"
dataset/ETHPy150Open Rapptz/discord.py/discord/message.py/Message.clean_content