Simple Error Handling for Prefix and App commands - discord.py

error_handler.py

import logging

import discord
from discord import app_commands
from discord.ext import commands


LOGGER: logging.Logger = logging.getLogger(__name__)


class CommandErrors(commands.Cog):
    
    def __init__(self, bot: commands.Bot) -> None:
        # Save the default handlers incase we have to unload this extension...
        self.original_command_error = bot.on_command_error
        self.original_app_error = bot.tree.on_error
        
        # Assign the new handlers to the bot...
        bot.on_command_error = self.on_command_error
        bot.tree.on_error = self.on_app_command_error
        
        self.bot = bot
    
    async def cog_unload(self) -> None:
        """Load the original error handlers back into the bot when this Cog unloads."""
        self.bot.on_command_error = self.original_command_error
        self.bot.tree.on_error = self.original_app_error
        
    async def send(
        self,
        content: str,
        /,
        context: commands.Context[commands.Bot] | discord.Interaction[commands.Bot],
        ephemeral: bool = True
    ) -> None:
        """Simple generic method for sending a response.
        
        This method catches and logs discord.HTTPExceptions.
        
        Parameters
        ----------
        content: str
            The content to send in the response.
        context: commands.Context | discord.Interaction
            The context or interaction surrounding the command or app command.
        ephemeral: bool
            Optional bool indicating whether the repsonse should attempted to be sent ephemerally. Defaults to True.
        """
        if isinstance(context, commands.Context):
            send = context.send
        else:
            send = context.response.send_message if not context.response.is_done() else context.followup.send

        try:
            await send(content=content, ephemeral=ephemeral)
        except discord.HTTPException as e:
            msg = f'Ignoring HTTPException in %r for %r: %s\n\n'
            LOGGER.error(msg, self.send.__name__, self.__class__.__name__, e, exc_info=e)
    
    async def on_command_error(self, ctx: commands.Context[commands.Bot], error: commands.CommandError) -> None:
        """Prefix command error handler."""
        
        # Don't continue if we have a command specific handler...
        if ctx.command and ctx.command.has_error_handler():
            return
        
        # Don't continue if we have a Cog error handler...
        elif ctx.cog and ctx.cog.has_error_handler():
            return
        
        error = getattr(error, 'original', error)
        ignored = (commands.CommandNotFound, commands.NotOwner)
        
        # Don't continue if the error is in ignored...
        if isinstance(error, ignored):
            return
        
        # Example of handling some command errors...
        # If we don't handle the Exception we log it to console...
        elif isinstance(error, commands.NoPrivateMessage):
            await self.send("This command can not be used in Private Messages.", context=ctx)
        elif isinstance(error, commands.DisabledCommand):
            await self.send("This command has been disabled by the owner.", context=ctx)
        else:
            LOGGER.error("Ignoring exception in command %s", ctx.command, exc_info=error)
        
    async def on_app_command_error(
        self,
        interaction: discord.Interaction[commands.Bot],
        error: app_commands.AppCommandError,
    ) -> None:
        """AppCommand error handler."""
        command = interaction.command
        
        # Default logging if the AppCommand is None...
        if command is None:
            LOGGER.error("Ignoring exception in command tree", exc_info=error)
            return
        
        # Don't continue if we have a command specific handler...
        if command.on_error:
            return
        
        # Example of responding to an error...
        if isinstance(error, app_commands.CommandOnCooldown):
            retry_after = error.cooldown.get_retry_after()
            await self.send(f"This command is on cooldown. Try again in {retry_after:.2f} seconds...", context=interaction)
        else:
            # Respond to all unhandled errors as an example... Could be removed to show the default response from Discord.
            # All unhandled errors are also logged to console...
            await self.send(f"**This application received an unhandled exception:**\n\n{error}", context=interaction)
            LOGGER.error('Ignoring exception in command %r', command.name, exc_info=error)


async def setup(bot: commands.Bot) -> None:
    await bot.add_cog(CommandErrors(bot))

error_handler_clean.py

import logging

import discord
from discord import app_commands
from discord.ext import commands


LOGGER: logging.Logger = logging.getLogger(__name__)


class CommandErrors(commands.Cog):
    
    def __init__(self, bot: commands.Bot) -> None:
        self.original_command_error = bot.on_command_error
        self.original_app_error = bot.tree.on_error
        
        bot.on_command_error = self.on_command_error
        bot.tree.on_error = self.on_app_command_error
        
        self.bot = bot
    
    async def cog_unload(self) -> None:
        """Load the original error handlers back into the bot when this Cog unloads."""
        self.bot.on_command_error = self.original_command_error
        self.bot.tree.on_error = self.original_app_error
        
    async def send(
        self,
        content: str,
        /,
        context: commands.Context[commands.Bot] | discord.Interaction[commands.Bot],
        ephemeral: bool = True
    ) -> None:
        """Simple generic method for sending a response.
        
        Parameters
        ----------
        content: str
            The content to send in the response.
        context: commands.Context | discord.Interaction
            The context or interaction surrounding the command or app command.
        ephemeral: bool
            Optional bool indicating whether the repsonse should attempted to be sent ephemerally. Defaults to True.
        """
        if isinstance(context, commands.Context):
            send = context.send
        else:
            send = context.response.send_message if not context.response.is_done() else context.followup.send

        try:
            await send(content=content, ephemeral=ephemeral)
        except discord.HTTPException as e:
            msg = f'Ignoring HTTPException in %r for %r: %s\n\n'
            LOGGER.error(msg, self.send.__name__, self.__class__.__name__, e, exc_info=e)
    
    async def on_command_error(self, ctx: commands.Context[commands.Bot], error: commands.CommandError) -> None:
        """Prefix command error handler."""
        if ctx.command and ctx.command.has_error_handler():
            return
        
        elif ctx.cog and ctx.cog.has_error_handler():
            return
        
        error = getattr(error, 'original', error)
        ignored = (commands.CommandNotFound, commands.NotOwner)
        
        if isinstance(error, ignored):
            return
        
        elif isinstance(error, commands.NoPrivateMessage):
            await self.send("This command can not be used in Private Messages.", context=ctx)
        elif isinstance(error, commands.DisabledCommand):
            await self.send("This command has been disabled by the owner.", context=ctx)
        else:
            LOGGER.error("Ignoring exception in command %s", ctx.command, exc_info=error)
        
    async def on_app_command_error(
        self,
        interaction: discord.Interaction[commands.Bot],
        error: app_commands.AppCommandError,
    ) -> None:
        """AppCommand error handler."""
        command = interaction.command
        
        if command is None:
            LOGGER.error("Ignoring exception in command tree", exc_info=error)
            return
        
        if command.on_error:
            return
        
        if isinstance(error, app_commands.CommandOnCooldown):
            retry_after = error.cooldown.get_retry_after()
            await self.send(f"This command is on cooldown. Try again in {retry_after:.2f} seconds...", context=interaction)
        else:
            await self.send(f"**This application received an unhandled exception:**\n\n{error}", context=interaction)
            LOGGER.error('Ignoring exception in command %r', command.name, exc_info=error)


async def setup(bot: commands.Bot) -> None:
    await bot.add_cog(CommandErrors(bot))

@Daudd yea, you're right. Fixed my code.

how to use this in my bot
i mean how to import this

@benjamonnguyen You don't have the right permissions to do whatever you're trying to do

how to use this in my bot i mean how to import this

you dont have to import anything to make use of it. just make sure that its in your cogs folder