TypeError: startswith first arg must be str or a tuple of str, not bytes

[schlopp]

Summary

TypeError: startswith first arg must be str or a tuple of str, not bytes

Reproduction Steps

Create webhook with a member's avatar url as the url

Minimal Reproducible Code

await channel.create_webhook(name="example name", avatar=member.avatar.url, reason="example reason")

Expected Results

I expected a webhook to be created

Actual Results

I received this exception:

Traceback (most recent call last):
  File "C:\Users\rdtla\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\LocalCache\local-packages\Python38\site-packages\discord\ext\commands\core.py", line 179, in wrapped
    ret = await coro(*args, **kwargs)
  File "C:\Users\rdtla\OneDrive\Documents\GitHub\impersonator\cogs\impersonation.py", line 19, in _say_command
    webhook: discord.Webhook = await channel.create_webhook(name="example name", avatar=member.avatar.url, reason="example reason")
  File "C:\Users\rdtla\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\LocalCache\local-packages\Python38\site-packages\discord\channel.py", line 567, in create_webhook
    avatar = utils._bytes_to_base64_data(avatar)  # type: ignore
  File "C:\Users\rdtla\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\LocalCache\local-packages\Python38\site-packages\discord\utils.py", line 482, in _bytes_to_base64_data
    mime = _get_mime_type_for_image(data)
  File "C:\Users\rdtla\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\LocalCache\local-packages\Python38\site-packages\discord\utils.py", line 468, in _get_mime_type_for_image
    if data.startswith(b'\x89\x50\x4E\x47\x0D\x0A\x1A\x0A'):
TypeError: startswith first arg must be str or a tuple of str, not bytes

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\rdtla\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\LocalCache\local-packages\Python38\site-packages\discord\ext\commands\bot.py", line 1045, in invoke
    await ctx.command.invoke(ctx)
  File "C:\Users\rdtla\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\LocalCache\local-packages\Python38\site-packages\discord\ext\commands\core.py", line 951, in invoke
    await injected(*ctx.args, **ctx.kwargs)
  File "C:\Users\rdtla\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\LocalCache\local-packages\Python38\site-packages\discord\ext\commands\core.py", line 188, in wrapped
    raise CommandInvokeError(exc) from exc
discord.ext.commands.errors.CommandInvokeError: Command raised an exception: TypeError: startswith first arg must be str or a tuple of str, not bytes

Intents

guilds members bans emojis integrations webhooks invites voice_states presences guild_messages dm_messages guild_reactions dm_reactions guild_typing dm_typing

System Information

• Python v3.8.10-final
• Novus v0.0.3-final
• aiohttp v3.7.4.post0
• system info: Windows 10 10.0.19043

Checklist

• I have searched the open issues for duplicates.
• I have shown the entire traceback, if possible.
• I have removed my token from display, if visible.

Additional Context

No response

[Jerrie-Aries]

The avatar parameter for .create_webhook() takes a bytes object, not a string. So Asset.url won't work.
You should retrieve the content of the Asset as a bytes object first, using await Asset.read(). So in your case it would be await member.avatar.read().

[schlopp]

The avatar parameter for .create_webhook() takes a bytes object, not a string. So Asset.url won't work. You should retrieve the content of the Asset as a bytes object first, using await Asset.read(). So in your case it would be await member.avatar.read().

Thank you, this helped me. I think the TypeError is still something worth fixing though

[4Kaylum]

What do you think should be fixed with this? This is working as intended - the avatar parameter doesn't take a URL.

[schlopp]

    if data.startswith(b'\x89\x50\x4E\x47\x0D\x0A\x1A\x0A'):
TypeError: startswith first arg must be str or a tuple of str, not bytes

is this not a bug in the code?

[4Kaylum]

No. You passed an incorrect set of data to the method (it takes a bytes-like object, not a URL) and it errored accordingly.