有没有办法检查固定的消息，并且只使用 discord.py 清除某些成员的消息?

I want to make a purge command similar to Dyne's, where you can input a user, and it doesn't purge pinned, only the user's messages (if you input a user). I've tried making a seperate check function, but it doesn't purge anything. I get no error, it just won't purge.

@commands.command()
    @commands.has_permissions(manage_messages=True)
    async def purge(self, ctx, user: discord.Member = None, num: int = 10000):
        if user:
            def check_func(user: discord.Member, message: discord.Message):
                return not msg.pinned
                return user.id
            await ctx.message.delete()
            await ctx.channel.purge(limit=num, check=check_func)
            verycool = await ctx.send(f'{num} messages deleted.')
            await verycool.delete()

        else:
            await ctx.message.delete()
            await ctx.channel.purge(limit=num, check=lambda msg: not msg.pinned)
            verycool = await ctx.send(f'{num} messages deleted.')
            await verycool.delete()

我在服务器上有管理消息的权限.有谁知道如何使 check_func 正常工作?

@commands.command()
@commands.has_permissions(manage_messages=True)
async def purge(self, ctx, num: int = None, user: discord.Member = None):
    if user:
        check_func = lambda msg: msg.author == user and not msg.pinned
    else:
        check_func = lambda msg: not msg.pinned

    await ctx.message.delete()
    await ctx.channel.purge(limit=num, check=check_func)
    await ctx.send(f'{num} messages deleted.', delete_after=5)