踢命令（discord.py）

Question

So I'm trying to make a kick command so that if the reason is nothing, then it says "no reason" instead of none. Don't ask why.

Here's my code:

@client.command()
@commands.has_permissions(kick_members=True)
async def kick(ctx, user: discord.Member, *, reason: str):
  if reason is None:
    await user.kick()
    await ctx.send(f"**{user}** has been kicked for **no reason**.")
  else:
    await user.kick(reason=reason)
    await ctx.send(f"**{user}** has been kicked for **{reason}**.")

And here's the error:

Ignoring exception in command kick:
Traceback (most recent call last):
  File "/opt/virtualenvs/python3/lib/python3.8/site-packages/discord/ext/commands/bot.py", line 903, in invoke
    await ctx.command.invoke(ctx)
  File "/opt/virtualenvs/python3/lib/python3.8/site-packages/discord/ext/commands/core.py", line 847, in invoke
    await self.prepare(ctx)
  File "/opt/virtualenvs/python3/lib/python3.8/site-packages/discord/ext/commands/core.py", line 784, in prepare
    await self._parse_arguments(ctx)
  File "/opt/virtualenvs/python3/lib/python3.8/site-packages/discord/ext/commands/core.py", line 699, in _parse_arguments
    kwargs[name] = await self.transform(ctx, param)
  File "/opt/virtualenvs/python3/lib/python3.8/site-packages/discord/ext/commands/core.py", line 535, in transform
    raise MissingRequiredArgument(param)
discord.ext.commands.errors.MissingRequiredArgument: reason is a required argument that is missing.

I don't understand why it says that "reason is a required argument that is missing" because I said that if reason is None it would say no reason?

Answer 1

If you assign None to the reason , then you can check it. For example reason = None . After that you can check in the commmand if the reason is None . Here is the code:

@client.command()
@commands.has_permissions(kick_members=True)
async def kick(ctx, user: discord.Member, *, reason = None):
  if not reason:
    await user.kick()
    await ctx.send(f"**{user}** has been kicked for **no reason**.")
  else:
    await user.kick(reason=reason)
    await ctx.send(f"**{user}** has been kicked for **{reason}**.")

Answer 2

You're getting that error because your function looks like this:

async def kick(ctx, user: discord.Member, *, reason: str):

Reason is not optional here, so it is a required argument . That means that calling this function without that argument will result in an error. Adding in a default value makes it optional.

def function(requiredArgument, optionalArgument=defaultValue)

In this case, defaultValue should be None . Now, when you don't pass in anything for that argument, it's default value will be used. That way, you no longer have to add a reason.