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

def on_command_error(self, error, ctx):
        ignored = (commands.NoPrivateMessage, commands.DisabledCommand, commands.CheckFailure,
                   commands.CommandNotFound, commands.UserInputError, discord.HTTPException)
        error = getattr(error, 'original', error)

        if isinstance(error, ignored):
            return

        if ctx.message.server:
            fmt = 'Channel: {0} (ID: {0.id})\nGuild: {1} (ID: {1.id})'
        else:
            fmt = 'Channel: {0} (ID: {0.id})'

        exc = traceback.format_exception(type(error), error, error.__traceback__, chain=False)
        description = '```py\n%s\n```' % ''.join(exc)
        time = datetime.datetime.utcnow()

        name = ctx.command.qualified_name
        author = '{0} (ID: {0.id})'.format(ctx.message.author)
        location = fmt.format(ctx.message.channel, ctx.message.server)

        message = '{0} at {1}: Called by: {2} in {3}. More info: {4}'.format(name, time, author, location, description)

        self.bot.logs['discord'].critical(message)

def has_permission(ctx: commands.Context) -> bool:
    """ Checks if a user is an administrator or if has the role
        that grants elevated permissions.

    :param ctx: The context to check the command in.
    :type ctx: commands.Context

    :return: True if the command succeeds, else raises an exception.
    :raises: commands.CheckFailure: If the check fails.
        message : "no permissions"
    """

    if isinstance(ctx.bot, PomodoroBot) and \
       ctx.bot.has_permission(ctx.message.author):
        return True
    raise commands.CheckFailure(message="no permissions")

def is_admin(ctx: commands.Context) -> bool:
    """ Checks if the author of the command is the administrator / owner
        of the bot.

    :param ctx: The context to check the command in.
    :type ctx: commands.Context

    :return: True if the command succeeds, else raises an exception.
    :raises: commands.CheckFailure: If the check fails.
        message : "not admin"
    """

    if isinstance(ctx.bot, PomodoroBot) and \
       ctx.bot.is_admin(ctx.message.author):
        return True
    raise commands.CheckFailure(message="not admin")

def channel_has_timer(ctx: commands.Context) -> bool:
    """ Checks if a channel has a valid timer set.

    :param ctx: The context to check the command in
    :type ctx: commands.Context

    :return: True if the command succeeds, else raises an exception.
    :raises: commands.CheckFailure: If the check fails.
        message : "timer not found"
    """

    if isinstance(ctx.bot, PomodoroBot):
        channel = ctx.bot.spoof(ctx.message.author, lib.get_channel(ctx))

        if ctx.bot.get_interface(channel).timer is not None:
            return True

    raise commands.CheckFailure(message="timer not found")

def unlocked_or_allowed(ctx: commands.Context) -> bool:
    """ Checks if a timer is unlocked, or if the author of the command
        has permissions to execute such command on a locked timer.

    :param ctx: The context to check the command in
    :type ctx: commands.Context

    :return: True if the command succeeds, else raises an exception.
    :raises: commands.CheckFailure: If the check fails.
        message : "timer locked"
    """

    if isinstance(ctx.bot, PomodoroBot) and \
       ctx.bot.is_locked(lib.get_channel(ctx)) and \
       not ctx.bot.has_permission(ctx.message.author):
            raise commands.CheckFailure(message="timer locked")
    return True

def on_command_error(ctx, error):
    if isinstance(error, commands.CommandNotFound):
        return

    # if isinstance(error, commands.CommandInvokeError):
    #   return print(error)

    errors = {
        commands.DisabledCommand: 'Command has been disabled.',
        commands.MissingPermissions: 'Invoker is missing permissions to run this command.',
        commands.BotMissingPermissions: 'Bot is missing permissions to run this command.',
        commands.CheckFailure: 'You are not allowed to run this command.'
    }

    for type, text in errors.items():
        if isinstance(error, type):
            return await ctx.send(errors[type])

    # argument error
    if isinstance(error, commands.UserInputError):
        bot.formatter.context = ctx
        bot.formatter.command = ctx.command
        return await ctx.send(f'Invalid argument(s) provided.\n```{bot.formatter.get_command_signature()}```')

    await ctx.send(f'An error occured in `{ctx.command.name}` invoked by {ctx.message.author}:\n```{error}```')
    #traceback.print_exception(type(exception), exception, exception.__traceback__, file=sys.stderr)

# blacklist check
# check is user is blacklister, or if it's a bot

def on_command_error(self, ctx, error):
        ignored = (commands.NoPrivateMessage, commands.DisabledCommand, commands.CheckFailure,
                   commands.CommandNotFound, commands.UserInputError, discord.Forbidden)
        error = getattr(error, 'original', error)

        if isinstance(error, ignored):
            return

        e = discord.Embed(title='Command Error', colour=0xcc3366)
        e.add_field(name='Name', value=ctx.command.qualified_name)
        e.add_field(name='Author', value=f'{ctx.author} (ID: {ctx.author.id})')

        fmt = f'Channel: {ctx.channel} (ID: {ctx.channel.id})'
        if ctx.guild:
            fmt = f'{fmt}\nGuild: {ctx.guild} (ID: {ctx.guild.id})'

        e.add_field(name='Location', value=fmt, inline=False)

        exc = ''.join(traceback.format_exception(type(error), error, error.__traceback__, chain=False))
        e.description = f'```py\n{exc}\n```'
        e.timestamp = datetime.datetime.utcnow()
        ch = self.bot.get_channel(LOGGING_CHANNEL)
        await ch.send(embed=e)

def on_command_error(self, ctx, error):
        """Command error handler"""
        manager = MessageManager(self.bot, ctx.author, ctx.channel, ctx.prefix, [ctx.message])

        if isinstance(error, commands.CommandNotFound):
            pass

        elif isinstance(error, commands.MissingRequiredArgument):
            pass

        elif isinstance(error, commands.NotOwner):
            pass

        elif isinstance(error, commands.NoPrivateMessage):
            await manager.say("You can't use that command in a private message", mention=False)

        elif isinstance(error, commands.CheckFailure):
            await manager.say("You don't have the required permissions to do that")

        elif isinstance(error, commands.CommandOnCooldown):
            await manager.say(error)

        elif isinstance(error, commands.CommandInvokeError):
            if isinstance(error.original, discord.errors.Forbidden):
                pass
            else:
                raise error

        else:
            raise error

        await manager.clear()

def define_error(self, ctx, err):
        if isinstance(err, commands.DisabledCommand) or isinstance(err, commands.CheckFailure):
            return
        await ctx.send('An error has occurred.')

def on_command_error(self, ctx, error):
        if isinstance(error, commands.CheckFailure) and await self.is_owner(ctx.author):
            # There is actually a race here. When this command is invoked the
            # first time, it's wrapped in a context manager that automatically
            # starts and closes a DB session.
            #
            # The issue is that this event is dispatched, which means during the
            # first invoke, it creates a task for this and goes on with its day.
            # The problem is that it doesn't wait for this event, meaning it might
            # accidentally close the session before or during this command's
            # reinvoke.
            #
            # This solution is dirty but since I'm only doing it once here
            # it's fine. Besides it works anyway.
            while ctx.session:
                await asyncio.sleep(0)

            try:
                async with ctx.acquire():
                    await ctx.reinvoke()
            except Exception as exc:
                await ctx.command.dispatch_error(ctx, exc)
            return

        # command_counter['failed'] += 0 sets the 'failed' key. We don't want that.
        if not isinstance(error, commands.CommandNotFound):
            self.command_counter['failed'] += 1

        cause = error.__cause__
        if isinstance(error, errors.ChiakiException):
            await ctx.send(str(error))
        elif type(error) is commands.BadArgument:
            await ctx.send(str(cause or error))
        elif isinstance(error, commands.NoPrivateMessage):
            await ctx.send('This command cannot be used in private messages.')
        elif isinstance(error, commands.MissingRequiredArgument):
            await ctx.send(f'This command ({ctx.command}) needs another parameter ({error.param})')
        elif isinstance(error, commands.CommandInvokeError):
            print(f'In {ctx.command.qualified_name}:', file=sys.stderr)
            traceback.print_tb(error.original.__traceback__)
            print(f'{error.__class__.__name__}: {error}'.format(error), file=sys.stderr)

def on_command_error(self, exception, ctx):
        if isinstance(exception, CheckFailure):
            print("{0} does not have permission to run `{1}`".format(ctx.message.author, ctx.command.name))
        elif isinstance(exception, CommandNotFound):
            # This is handled in CustomCommands
            pass
        else:
            pprint(exception)
            await self.on_error("on_command_error", exception, ctx)

def on_command_error(ctx, error):
    if isinstance(error, commands.NoPrivateMessage):
        await edit(ctx, content='\N{HEAVY EXCLAMATION MARK SYMBOL} Only usable on Servers', ttl=5)
    elif isinstance(error, commands.CheckFailure):
        await edit(ctx, content='\N{HEAVY EXCLAMATION MARK SYMBOL} No Permissions to use this command', ttl=5)
    elif isinstance(error, commands.CommandInvokeError):
        log.error('In {0.command.qualified_name}:\n{1}'.format(ctx, ''.join(traceback.format_list(traceback.extract_tb(error.original.__traceback__)))))
        log.error('{0.__class__.__name__}: {0}'.format(error.original))


# Increase use count and log to logger

def p_error(error, ctx):
    if isinstance(error, commands.BadArgument):
        await bot.say("That\'s not a number...")
    if isinstance(error, commands.CheckFailure):
        await bot.say("Insufficent permissions")

def on_command_error(exception, context):
    if type(exception) == commands.CommandOnCooldown:
        await bot.send_message(context.message.channel,
                               "!{} is on cooldown for {:0.2f} seconds.".format(
                                   context.command, exception.retry_after))
    elif type(exception) == commands.CommandNotFound:
        cmd = context.message.content.split()[0][1:]
        try:
            closest = get_close_matches(cmd.lower(), list(bot.commands))[0]
        except IndexError:
            await bot.send_message(context.message.channel,
                                   "!{} is not a known command."
                                   .format(cmd))
        else:
            await bot.send_message(context.message.channel,
                                   "!{} is not a command, did you mean !{}?"
                                   .format(cmd, closest))
    elif type(exception) == commands.CheckFailure:
        await bot.send_message(context.message.channel,
                               "You failed to meet a requirement for that "
                               "command.")
    elif type(exception) == commands.MissingRequiredArgument:
        await bot.send_message(context.message.channel,
                               "You are missing a required argument for that "
                               "command.")
    else:
        await bot.send_message(context.message.channel,
                               "Unhandled command error ({})"
                               .format(exception))

    print('Ignoring exception in command {}'.format(context.command),
          file=sys.stderr)
    traceback.print_exception(type(exception), exception,
                              exception.__traceback__, file=sys.stderr)

def on_command_error(self, error, ctx: commands.Context):

        log = lib.get_author_name(ctx)
        send = None

        if isinstance(error, commands.CheckFailure):

            if str(error) == "timer not found":
                send = "No timer found for this channel."
                log += " tried to interact with a nonexistent timer."

            elif str(error) == "timer locked":
                send = "You are not allowed to modify this timer."
                log += " tried to modify a locked timer without permissions."

            elif str(error) == "no permissions" or str(error) == "not admin":
                send = "You do not have permission to do this!"
                log += (" tried to execute a command and failed, " +
                        "lacked permissions.")
            else:
                send = "Timers are not allowed in this channel."
                log += " tried to start a timer in a non-whitelisted channel."

        elif isinstance(error, commands.CommandNotFound):
            send = "Command not found: `" + ctx.invoked_with + "`."
            log += " tried to execute a nonexistent command: `{}`."\
                .format(ctx.invoked_with)

            alt = None
            for name, command in self.bot.commands.items():
                if ctx.invoked_with == name:
                    alt = name
                elif isinstance(command, commands.GroupMixin):
                    for sub_name, sub_command in command.commands.items():
                        if ctx.invoked_with == sub_name:
                            alt = name + " " + sub_name

            if alt is not None:
                send += " Did you mean `" + alt + "`?"

        elif isinstance(error, commands.CommandInvokeError):
            lib.log_cmd_stacktrace(error)
            return
        else:
            log = str(error)

        lib.log(log, channel_id=lib.get_channel_id(ctx), level=logging.WARN)
        await self.bot.safe_send(lib.get_channel(ctx), send,
                                 delete_after=self.bot.ans_lifespan)

def on_command_error(error, ctx):
    if isinstance(error, commands.CommandNotFound):
        return
    if isinstance(error, commands.DisabledCommand):
        return
    try:
        if isinstance(error.original, discord.Forbidden):
            return
        elif isinstance(error.original, discord.HTTPException) and 'empty message' in str(error.original):
            return
        elif isinstance(error.original, aiohttp.ClientOSError):
            return
    except AttributeError:
        pass

    if isinstance(error, commands.BadArgument):
        fmt = "Please provide a valid argument to pass to the command: {}".format(error)
        await bot.send_message(ctx.message.channel, fmt)
    elif isinstance(error, commands.CheckFailure):
        fmt = "You can't tell me what to do!"
        await bot.send_message(ctx.message.channel, fmt)
    elif isinstance(error, commands.CommandOnCooldown):
        m, s = divmod(error.retry_after, 60)
        fmt = "This command is on cooldown! Hold your horses! >:c\nTry again in {} minutes and {} seconds" \
            .format(round(m), round(s))
        await bot.send_message(ctx.message.channel, fmt)
    elif isinstance(error, commands.NoPrivateMessage):
        fmt = "This command cannot be used in a private message"
        await bot.send_message(ctx.message.channel, fmt)
    elif isinstance(error, commands.MissingRequiredArgument):
        await bot.send_message(ctx.message.channel, error)
    else:
        now = datetime.datetime.now()
        with open("error_log", 'a') as f:
            print("In server '{0.message.server}' at {1}\nFull command: `{0.message.content}`".format(ctx, str(now)),
                  file=f)
            try:
                traceback.print_tb(error.original.__traceback__, file=f)
                print('{0.__class__.__name__}: {0}'.format(error.original), file=f)
            except:
                traceback.print_tb(error.__traceback__, file=f)
                print('{0.__class__.__name__}: {0}'.format(error), file=f)

def on_command_error(ctx, error):
    if ctx.message in thinker.messages:
        await thinker.stop_thinking(ctx.message)

    try:
        if isinstance(error, commands.CommandNotFound):
            cmd = ctx.message.content[1:].split(" ")[0]
            if cmd in deprecated_commands:
                await ctx.send(f"You shouldn't use `?{cmd}` anymore. It's *deprecated*. Try `?{deprecated_commands[cmd]}` instead.")
                return
            elif cmd == "" or cmd.startswith("?") or cmd.startswith("!"):
                return # These were probably not meant to be commands

            if cmd.lower() in bot.commands:
                new_message = ctx.message
                new_message.content = "?" + cmd.lower() + ctx.message.content[len(cmd) + 1:]
                await bot.process_commands(new_message)
            elif await invalid_command_reporting(ctx):
                await ctx.send(f"?? Ya I dunno what a '{cmd}' is, but it ain't a command. Try `?help` fer a list of things that ARE commands.") 
        elif isinstance(error, commands.CheckFailure):
            print("(suppressed)")
            return # The user does not have permissions
        elif isinstance(error, commands.MissingRequiredArgument):
            await ctx.send(embed=await bot.formatter.format_as_embed(ctx, ctx.command))
        elif isinstance(error, commands.BadArgument):
            signature = await get_cmd_signature(ctx)
            await ctx.send((
                "Thats the wrong type of argument for that command.\n\n"
                f"Ya gotta do it like this:\n`{signature}`\n\n"
                f"Try `?help {ctx.command}` for a more detailed description of the command"))
        elif isinstance(error, commands.CommandInvokeError) and isinstance(error.original, discord.errors.Forbidden):
            await print_missing_perms(ctx, error)
        elif isinstance(error, commands.CommandInvokeError) and isinstance(error.original, discord.errors.HTTPException):
            await ctx.send("Looks like there was a problem with discord just then. Try again in a bit.")
        elif isinstance(error, commands.CommandInvokeError) and isinstance(error.original, UserError):
            await ctx.send(error.original.message)
        else:
            await ctx.send("Uh-oh, sumthin dun gone wrong ??")
            trace_string = report_error(ctx.message, error, skip_lines=4)
            if settings.debug:
                await ctx.send(f"```{trace_string}```")
    except discord.errors.Forbidden:
        await ctx.author.send("Looks like I don't have permission to talk in that channel, sorry")

def on_command_error(error, ctx):
    language = prefs.getPref(ctx.message.server, "language")
    if isinstance(error, commands.NoPrivateMessage):
        await bot.send_message(ctx.message.author, _(':x: This command cannot be used in private messages.', language))
    elif isinstance(error, commands.DisabledCommand):
        await bot.send_message(ctx.message.author, _(':x: Sorry. This command is disabled and cannot be used.', language))
    elif isinstance(error, commands.CommandInvokeError):
        print('In {0.command.qualified_name}:'.format(ctx), file=sys.stderr)
        traceback.print_tb(error.original.__traceback__)
        print('{0.__class__.__name__}: {0}'.format(error.original), file=sys.stderr)

        myperms = ctx.message.channel.permissions_for(ctx.message.server.me)
        can_send = myperms.add_reactions and myperms.create_instant_invite
        if can_send:
            error_report = _("Send an error report?", language)
        else:
            error_report = _("Sadly, I need the `add_reactions` and `create_instant_invite` permissions to be able to send an error report.", language)

        msg = await comm.message_user(ctx.message, _(":x: An error (`{error}`) happened while executing `{command}`, here is the traceback: ```\n{tb}\n```\n{error_report}", language).format(**{
            "command"     : ctx.command.qualified_name,
            "error"       : error.original.__class__.__name__,
            "tb"          : "\n".join(traceback.format_tb(error.original.__traceback__, 4)),
            "error_report": error_report
        }))

        if can_send:
            yes = "\N{THUMBS UP SIGN}"
            no = "\N{THUMBS DOWN SIGN}"
            await bot.add_reaction(msg, yes)
            await bot.add_reaction(msg, no)
            res = await bot.wait_for_reaction(emoji=[yes, no], user=ctx.message.author, message=msg, timeout=120)
            if res:
                reaction, user = res
                emoji = reaction.emoji
                if emoji == yes:

                    msg = await comm.message_user(ctx.message, _(":anger_right: Creating an invite for the error report...", language))
                    support_channel = discord.utils.find(lambda c: str(c.id) == '273930986314792960', discord.utils.find(lambda s: str(s.id) == '195260081036591104', bot.servers).channels)
                    invite = await bot.create_invite(ctx.message.channel, max_uses=5)
                    invite = invite.url
                    await bot.edit_message(msg, _(":anger_right: Sending error report...", language))

                    await bot.send_message(support_channel, _(":hammer: {date} :hammer:").format(date=int(time.time())))
                    await bot.send_message(support_channel, await comm.paste(_("{cause}\n\n{tb}").format(cause=error.original.__class__.__name__,
                                                                                                         tb="\n".join(traceback.format_tb(error.original.__traceback__))), "py"))
                    await bot.send_message(support_channel, invite)
                    await bot.edit_message(msg, _(":ok: Error report sent, thanks. :)", language))
                    return
            await comm.message_user(ctx.message, _("OK, I won't send an error report.", language))

    elif isinstance(error, commands.MissingRequiredArgument):
        await comm.message_user(ctx.message, _(":x: Missing a required argument. ", language) + (("Help: \n```\n" + ctx.command.help + "\n```") if ctx.command.help else ""))
    elif isinstance(error, commands.BadArgument):
        await comm.message_user(ctx.message, _(":x: Bad argument provided. ", language) + (("Help: \n```\n" + ctx.command.help + "\n```") if ctx.command.help else ""))
        # elif isinstance(error, commands.CheckFailure):
        # await comm.message_user(ctx.message, _(":x: You are not an admin/owner, you don't have enough exp to use this command, or you are banned from the channel, so you can't use this command. ", language) + (("Help: \n```\n" + ctx.command.help + "\n```") if ctx.command.help else ""))

def on_command_error(ctx, error):
        """The event triggered when an error is raised while invoking a command.
        ctx   : Context
        error : Exception"""

        if hasattr(ctx.command, 'on_error'):
            return

        cog = ctx.cog
        if cog:
            attr = f'_{cog.__class__.__name__}__error'
            if hasattr(cog, attr):
                return

        error = getattr(error, 'original', error)

        ignored = (commands.CommandNotFound, commands.UserInputError)
        if isinstance(error, ignored):
            return

        handler = {
            discord.Forbidden: '**I do not have the required permissions to run this command.**',
            commands.DisabledCommand: f'{ctx.command} has been disabled.',
            commands.NoPrivateMessage: f'{ctx.command} can not be used in Private Messages.',
            commands.CheckFailure: '**You aren\'t allowed to use this command!**',
            ExplicitCheckFailure: f'This command can only be used in a **NSFW** channel.',
            InvalidChannelCheck: f'{ctx.command} can only be used in a server',
            BotPermissionsCheck: 'For **any** of the moderation commands, the bot must be given\n'
                                 'Manage Messages, Manage Nicknames, Kick Members and Ban Members'
        }

        try:
            message = handler[type(error)]
        except KeyError:
            pass
        else:
            return await ctx.send(message)

        embed = discord.Embed(title=f'Command Exception', color=discord.Color.red())
        embed.set_footer(text='Occured on')
        embed.timestamp = datetime.datetime.utcnow()

        exc = ''.join(traceback.format_exception(type(error), error, error.__traceback__, chain=False))
        exc = exc.replace('`', '\u200b`')
        embed.description = f'```py\n{exc}\n```'

        embed.add_field(name='Command', value=ctx.command.qualified_name)
        embed.add_field(name='Invoker', value=ctx.author)
        embed.add_field(name='Location', value=f'Guild: {ctx.guild}\nChannel: {ctx.channel}')
        embed.add_field(name='Message', value=ctx.message.content)

        await ctx.bot.get_channel(368477860387880960).send(embed=embed)