Python discord.ext.commands 模块，has_permissions() 实例源码

def add_perms(self, ctx, *msg: str):
        """Sets up custom permissions on the provided command
        Format must be 'perms add <command> <permission>'
        If you want to open the command to everyone, provide 'none' as the permission
        EXAMPLE: !perms add skip ban_members
        RESULT: No more random people voting to skip a song"""

        # Since subcommands exist, base the last word in the list as the permission, and the rest of it as the command
        command = " ".join(msg[0:len(msg) - 1])
        try:
            permissions = msg[len(msg) - 1]
        except IndexError:
            await self.bot.say("Please provide the permissions you want to setup, the format for this must be in:\n"
                               "`perms add <command> <permission>`")
            return

        cmd = utils.find_command(self.bot, command)

        if cmd is None:
            await self.bot.say(
                "That command does not exist! You can't have custom permissions on a non-existant command....")
            return

        # If a user can run a command, they have to have send_messages permissions; so use this as the base
        if permissions.lower() == "none":
            permissions = "send_messages"

        # Convert the string to an int value of the permissions object, based on the required permission
        # If we hit an attribute error, that means the permission given was not correct
        perm_obj = discord.Permissions.none()
        try:
            setattr(perm_obj, permissions, True)
        except AttributeError:
            await self.bot.say("{} does not appear to be a valid permission! Valid permissions are: ```\n{}```"
                               .format(permissions, "\n".join(valid_perms)))
            return
        perm_value = perm_obj.value

        # Two cases I use should never have custom permissions setup on them, is_owner for obvious reasons
        # The other case is if I'm using the default has_permissions case
        # Which means I do not want to check custom permissions at all
        # Currently the second case is only on adding and removing permissions, to avoid abuse on these
        for check in cmd.checks:
            if "is_owner" == check.__name__ or "has_permissions" in str(check):
                await self.bot.say("This command cannot have custom permissions setup!")
                return

        key = ctx.message.server.id
        entry = {'server_id': key,
                 'permissions': {cmd.qualified_name: perm_value}}

        if not await utils.update_content('server_settings', entry, key):
            await utils.add_content('server_settings', entry)

        await self.bot.say("I have just added your custom permissions; "
                           "you now need to have `{}` permissions to use the command `{}`".format(permissions, command))