how to check for file extension in discord.py

Question

i am creating a python discord bot, and i have a function that if a message is sent in a certain channel, it randomly sends out a response,everything works fine but i want to restrict the bot to react only when the sent message contains a png, jpg or jpeg file

heres the code(look for the bottom if str(message.channel) statement):

@client.event
async def on_message(message):
    await client.process_commands(message)
    if str(message.channel) not in restr:
            if message.content == ".sabaton":
                random.seed(time.time())
                randnum = random.randint(0, len(songs) - 1)
                await message.channel.send(file=discord.File(songs[randnum]))
            elif message.content == ".time":
                await message.channel.send(f"Current time is {time.localtime()}")
            elif message.content == ".pmsh":
                await message.channel.send(help)
            if client.user.mention in message.content.split():
                await message.channel.send('Дарова гандон(иха),мой префикс "."')
    if str(message.channel) == "🥳творчество🥳":
        random.seed(time.time())
        rn3 = random.randint(1,2)
        if rn3 == 1 and message.author.bot == False:
            await message.channel.send("Заебись творчество")
        elif rn3 == 2 and message.author.bot == False:
            await message.channel.send("Фигня творчество")

Answer 1

Attachments in discord.py have information about their file type in their content_type attribute. This should hopefully make for cleaner code too!

Apart from the access, @Sofi's logic still applies:

for attachment in message.attachments:
    if attachment.content_type in ('image/jpeg', 'image/jpg', 'image/png'):
       # Your Logic Here

If you just need to check if something is an image, your code can be simpler:

for attachment in message.attachments:
    if 'image' in attachment.content_type:
         # Your Logic Here!

Answer 2

You can use the following conditions to restrict it:

if message.attachments[0].url.endswith('PNG') or message.attachments[0].url.endswith('JPG') or message.attachments[0].url.endswith('JPEG'):
    pass
else:
    pass

Change the pass according to your content.