Selecting random user from ctx.guild.members (discordpy)

I dont get whats wrong with this.. how could i fix it?

for users in ctx.guild.members:
        winner = random.choice(users)

    await channel.send(f"Congratulations! {winner} won {prize}!")

Traceback:

AttributeError: 'NoneType' object has no attribute 'id'
Ignoring exception in command giveaway:
Traceback (most recent call last):
  File "C:\Users\Zsombor\Desktop\Dexton\Cogs\giveaway.py", line 115, in giveaway
    winner = random.choice(users)
TypeError: object of type 'Member' has no len()

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

Traceback (most recent call last):
discord.ext.commands.errors.CommandInvokeError: Command raised an exception: TypeError: object of type 'Member' has no len()

>Solution :

The random.choice() takes a random item out of a list. So if you execute it on a single object, you get that error. In your case, a for loop is not necessary, just do

winner = random.choice(ctx.guild.members)