我正在尝试使用Python创建一个Discord BOT。我正在创建不同类型的函数，现在我想创建一个函数，允许机器人在有人加入服务器时在常规通道中发送消息

import discord
import random

from discord.ext import commands

token = 'BOT_TOKEN'
client = commands.Bot(command_prefix = '!')

@client.event
async def on_ready():
    print(f'{client.user.name} is now ready')

@client.command(aliases = ['ask', 'chiedi'])
async def _ask(ctx, *, question):
    file_object = open("quotes.txt")
    quotes = file_object.readlines()
    file_object.close()

    rnd = random.choice(quotes)
    await ctx.send(rnd)

@client.event
async def on_message(message):
    author = message.author
    content = message.content
    log = '{}: {}'.format(author, content)
    with open("logs.txt", "a+") as my_file:
        my_file.write(log + "\n")
        my_file.close()

'''
func print_msg
    once the user joins the server
    print message to greet him

'''

client.run(token)

我希望输出类似“Username已加入我们的服务器！欢迎”